Alex McFerron's Coding and Math Blog

How to install Windows Phone Toolkit

2012-01-17T02:52:00.000-08:00

1. Download NuGet package manager
Download Nuget

2. Go to Visual Studio 2010 Express for Windows phone -> Tools -> Library Package Manager -> Manage NuGet Packages for Solution...

3. Search "Windows Phone Tookit"

4. You should see Silverlight for Windows Phone Toolkit pop up... Install it for the solution

5. To test that it is installed. Go to Expression Blend. Right click on your solution and choose Expression Blend.

6. Go to the last symbol on the toolbar (>>), click on it to expand it.

7. Type "wrap" into the search box and if you find it, then Windows Phone Toolkit has been installed properly.

Inspired at CodeMash

2012-01-11T07:08:00.000-08:00

The CodeMash conference is a perfect way to start the new year. No one could fail to be inspired by this conference. Well, ok, I'm sure someone could, but I couldn't. I'm completely geeked about this conference. Choosing between the sessions is traumatic though, it is brutal. I want to attend them all.

Code Mash

I'm focusing on windows phone for my precompiler (workshop), Jeff Blankenburg

and I'm going to hit more windows phone talks by Jeff, and by Jesse Liberty. I'm going to An Intro to Expression Blend by Joel Cochran, and definitely the Windows 8 talk by James Bender.

Who doesn't love a great conference? Well, this is the best I've seen. You can really tell its run by and for developers. They handed out nice swag but no plastic bag filled with paper. It is just classy in ways that are hard to describe. It is day one and already its my favorite conference.

Becoming An Expert

2011-11-12T15:26:00.000-08:00

At work I heard a great talk on Thursday from Rob Garrison about how to focus on a technical track career. The talk was really great and since I want a technical track career, I was interested in what he said.

One important point me made was that he said, you must become an expert in something.

However, after the talk, I was left wondering more about exactly how one picks what to be an expert in that would result in a strong technical career. This is a moving target.

1. How broad should the topic be?
a. MVC
b. All topics related to web development with ASP.NET and C#

I guess the answer should be to become in expert in the widest amount of topics you can realistically cover because at some point there is a limit to what you can do, given there are 24 hours in a day.

2. What technology to choose?
a. MVC
b. F#

I think the answer should be something that is going to be relevant to your current job or a job you want to have soon because if you choose something that isn't going to be applied at work then you will learn it but never use it. Use it or loose it!

3. Should you focus on something internal or external.

I think the answer to this is both. I think you need to pick one thing that is proprietary and one thing that is industry wide. So, I guess that means we need to become an expert in at least two things to build our careers, at least.

4. Fundamentals and being good at your job as is comes first.

I think that becoming an expert is a bit out of a person's reach if they aren't rocking out their daily responsiblities and the fundamentals of what they are doing. I think one needs to be rocking this out before they take on more of a load.

the times they are a changin'

2011-11-07T16:31:00.001-08:00

C# programming is changing programming paradigms. When we switched from procedural programming to object oriented programming we received new languages. C++ morphed out of C and Java hit the schene.

I purchased this book today Programming RX and Linq and the introduction explains how we are increasingly at odds with our current Object Oriented Programming way of life.

However, we are still coding C#. We're not calling it some other name and the paradigms are co-existing in the same language.

The future seems to be about functional programming, LINQ, dynamic language runtime, lambda expressions, anonymous delgates, etc... and a lot of these things are just plain different from basic OOP or even in conflict with OOP.

In the intro it says that that locks, threads, and events are pretty much the assembly langauge tools for asynchronous coding. Our tools haven't kept up with the changes.

I wonder why we don't get a new name, like C#Async or something to kind of warn us that everything is different now?

You have no talent! You aren't a natural!

2011-10-01T10:11:00.001-07:00

A lot of software engineers have a desire to be great craftsman. I am no different. I work ticket by ticket. Each time I do a ticket there is a product {release notes, software changes, a new install of the software, and documentation placed in the ticket}. I want my tickets and code to be logical, concise, and correct. I want to be able to do this very quickly and use the latest technology and the best technique. I want to communicate between groups of people inside of my organization as well as the clients we serve so well that the finished product makes the client and the user happy and content. I want to spread happiness and cooperation through the entire experience. I want the software to be bug free even of edge cases. This is the life quest of a software engineer.

I don't feel I am a beginner at this, but if you look at it from a different angle, we are all beginning a new journey each day. Today, I am at the beginning of trying to be better than I was yesterday. Believe me, I have failed at all of the above many times.

I sometimes feel that my desire to be better technically is a sign of weakness. This is more true about technical skills than soft skills or sports. If I say I want to be a better soccer player, I often get pointers right away and I get a few things to practice that change my playing. If I say I want to be learn to be less brash in my communication style I'm often offered some advice, like take a walk before a heavy phone call. However, if I admit where I would like to improve technically then a sort of atmosphere is created where my natural abilities and talent seem to be up for discussion or a matter of question.

The worst thing, is that all this judgement hits my self-doubt and becomes a Molotov cocktail of paralysis. It can then be disastrous for both me and for the profession. Who knows how many people have dropped out of math, science, and technical fields because they lacked talent and weren't naturals?

I tutor mathematics to kids and I can't tell you how many times I hear the words "I'm not good at math". This is from very intelligent kids who aren't out of high school. Honestly, I want to say, you don't even know what math is yet. You don't know the first thing about it or your ability to do it or not do it. I want to tell them that no one is good at math who doesn't work at it.

I think that what separates math people from non-math people in our culture is that math people continue doing math and don't spend anytime thinking they aren't math people. They just keep going on the journey. The older I get, the more it is obvious that a lot of really capable people quit the journey. I admit, this journey isn't for everyone. Its hard work. It takes focus. You have to want to do it. The financial rewards aren't really there in proportion to the work. But what really hurts me is that there are people who want to do it and quit. They change majors, go home, seek other work all because they have it in their heads that they lack talent and aren't naturals. The profession looses when this happens.

Does it really matter how long it took Ernest Hemingway or Jack Kerouac to become great writers? Not to me. What matters is that they got there. They inspired and they lived and they created. How inspirational.

As a software engineer and a math tutor, my life's work will most likely not be worshiped by large audiences like great American novels but all the same, the people around me will notice a difference. My clients, the people I tutor, coworkers, managers and most importantly of course is myself. I will know that I did my best. I will know that I became as "talented" as I could. After years of hard work and refinement, I'll be called talented.

——————–
From Ira Glass . . .
“What nobody tells people who are beginners — and I really wish someone had told this to me . . . is that all of us who do creative work, we get into it because we have good taste. But there is this gap. For the first couple years you make stuff, and it’s just not that good. It’s trying to be good, it has potential, but it’s not. But your taste, the thing that got you into the game, is still killer. And your taste is why your work disappoints you. A lot of people never get past this phase. They quit. Most people I know who do interesting, creative work went through years of this. We know our work doesn’t have this special thing that we want it to have. We all go through this. And if you are just starting out or you are still in this phase, you gotta know it’s normal and the most important thing you can do is do a lot of work. Put yourself on a deadline so that every week you will finish one story. It is only by going through a volume of work that you will close that gap, and your work will be as good as your ambitions. And I took longer to figure out how to do this than anyone I’ve ever met. It’s gonna take awhile. It’s normal to take awhile. You’ve just gotta fight your way through.”

——————–

The War of Art

2011-09-28T05:39:00.000-07:00

I'm reading the War of Art by Steven Pressfield

War of Art

I just started reading and I’m not sure I have resistance to work, but rather too much work. Most of the “work” isn’t towards my personal goals but I’m buried in it.

Can anyone relate to that?

Math .NET Libraries - Bueller... Bueller... Bueller?

2011-07-10T20:23:00.000-07:00

I've spent some time today trying to find .NET libraries and tools to explore mathematics and I have to report that it seems like slim pickings!

There are a few that cost money, but hey, I'm living off a developer's salary so I can't afford to buy software. Wish I could. But, this is 2011 and I'm afraid to spend money like everyone else.

As far as open source goes...
Math.NET I had a hard time finding documentation or samples using this project that helped me see how I could use it for exploration of calculus. I did figure out how to get up and running with some combinatorics examples but right now I'm reading calculus. Maybe its better for other topics other than calc?

Smart Math Library The documentation looks pretty extensive but I haven't made much time to explore.

Microsoft Graphics calculator sample
I think this sample is to teach WPF but I will take a look at it and see how they coded up a fairly basic graphics calculator.

Looks like there is a lot of work and opportunity in this area.

Get Inspired!

2011-07-09T13:36:00.001-07:00

Star Trek - TV intro (season 1) (1966)

JavaScript - buck up!

2011-07-08T07:27:00.000-07:00

This is an excellent talk that is a must see.
Rebecca Murphy, The JQuery Divide

"Learning JavaScript used to mean you weren't a "serious software developer". Today, not learning JavaScript means the same thing."
-MonkChips

Did you know that JavaScript is a prototype-based object oriented scripting language that is dynamically typed and that it’s a functional language because it has closures and supports higher-order functions? I didn't either until now.

Quick Start - Javascript Dojo and ASP.NET

2010-11-19T17:52:00.000-08:00

1. Create a hello world ASP.NET application and make sure its hooked into IIS

2. Create a directory at the same level as your project files named dojoroot and download the dojo files to this location
C:\Inetpub\wwwroot\HelloWorld\dojoroot

3. Add the following code to the project in the aspx page inside of the HTML HEAD tags:

<style type="text/css">
@import "dojoroot/dijit/themes/tundra/tundra.css";
@import "dojoroot/dojo/resources/dojo.css";
</style>

<script type="text/javascript" src="dojoroot/dojo/dojo.js" djConfig="parseOnLoad: true">
</script>

<script type="text/javascript">
dojo.require("dojo.parser");
dojo.require("dijit.form.Button");
dojo.require("dijit.form.TextBox");

dojo.addOnLoad(function(){
dojo.connect(dijit.byId("button"), "onClick", function(evt) {
dijit.byId("text").setValue("Welcome to Dojo");
});
});
</script>

4. Add the following code to the .aspx page inside of the body tags

<button id="button" dojoType="dijit.form.Button">
Click me
</button>

<input id="text" type="text" maxlength="25" dojoType="dijit.form.TextBox">
</input>

5. Make sure this is added to the head tag
<body class="tundra">

Learning LINQ using Combinatorics

2010-05-12T03:29:00.000-07:00

OK. This is just soooo cool!

Solving Combinatory Problems with LINQ by Octavio Hernandez

and in this article Octavio gives another link:

Using Linq to Solve Problems

This is just sooooo COOL! I'm definitly going to be reading these and talking about them!

Pluralsight Podcast

2010-04-21T11:36:00.000-07:00

I am on a podcast with Sarah Gray. We are talking about the DevChix group. Other women are interviewed also. I loved listening to the interviewer and the other women interviewing. This is a great podcast and a great topic.

Pluralsight Podcast

list of women interviewed.....

Meagon Marshall
Carey Payette
Sarah Dutkiewicz
Sarah Gray
Alex McFerron

cheers,
alex

The Future of Java?

2010-04-15T07:07:00.000-07:00

James Gosling leaving Oracle

This is an interesting drama and the future of Java is now in Oracle's hands. Oracle now runs sun microsystems and evidently there is a big culture shift between the two companies. James Gosling, Jonathan Schwartz, Tim Bray, Simon Phipps, and Scott McNealy have all left. It is a new day for Java.

Java today is the most popular programming language in the world if you use internet searching to determine language popularity.

When I first learned Java in school I loved it. We had been programming in C and C++ and my college switched to Java. The first thing that I noticed about it was its API documentation. It was easy to find, understand, and learn. I loved being able to automatically generate my javadocs and use junit for unit testing and ant for building my projects.

Many years later I'm still working in Java. Currently, I'm using it to work on my research poker project. We choose java for this project because it will run on linux as well as windows with ease and many of the existing academic based poker academy api's are written in Java.

Only time will tell what will happen with the future of Java, but it is in Oracle's hands.

Making It Big In Software - A book review

2010-04-13T22:12:00.000-07:00

I am currently reading Making It Big In Software by Sam Lightstone. I love this book!
Amazon.com Link to Book
This book interviews movers and shakers of the software industry. I am finding the book to be very informative and inspirational. First it defines what it means to be a big shot in software. These are people who impact software innovation, write books, publish papers, and present lectures. They code famous products and create new paradigms. The book focuses on the fact that great innovators in software become influential by giving the market what the market accepts at the right time and how to increase your chances of this tipping point. Lastly, this book talks a lot about soft skills and hard skills and how to grown and maintain both. I highly recommend this book to anyone in software at any stage in their career. I'm loving it!

Poker Players vs. the Computer

2010-01-28T14:56:00.001-08:00

This is a great cartoon that explains the current state of affairs regarding poker playing computers

Wired Cartoon

Becoming a Techincal Leader

2009-12-22T08:41:00.000-08:00

I am switching gears.

I’ve decided not to pursue the PHD just yet. Instead I want to focus on becoming a technical leader in industry. So, I have started reading a book at work titled “The 21 Irrefutable Laws of Leadership” by John C. Maxwell. I’m reading it and reflecting on how I can become a strong technical leader. Also, what does it even mean to be a technical leader?

Chapter 5 of the book is titled “The Law of Addition” and in my mind this helps me organize what I would like to work towards achieving with this blog and in life in general. The chapter is all about adding value to others lives. It lists out a few major ways to do this:
1) Truly value others
2) Make ourselves more valuable to others
3) Know and relate to what others value
4) Do things that are good for everyone with the big picture in mind

Out of this list, it is number 2 that stands out as the most difficult for me with the goal of wanting to be a technical leader. It makes sense that in order to be a technical leader you would need to know things but in addition to knowing them you also need to communicate them in a way that is in line with number 1, 3, and 4 of the list.

I am doing some relfection on what it means to be a technical leader on my team at work, at my company and in the industry in general. I want to be a stronger leader at each of these three levels.

Here is a link to the book:
Laws of Leadership Book

Grace Hopper Celebration Post 2

2009-10-09T12:41:00.000-07:00

The Grace Hopper Celebration was amazing and life changing. I absolutely loved being there and meeting so many other women who are interested in computer science. I believe that this is a MUST attend conference for any woman interested in computer science. Go at least least once! It is a mix of academic and industry topics.

The first reason this conference is so great is the mirroring. I can not explain why seeing someone who is like you is so important but I can tell you first hand that it is key. For some reason, seeing other women who are successful and interested in computer science is just very motivating. I came back from the conference very energized.

Another aspect of the conference that is life changing is the casual mentoring. It is easy to meet people further along on similar paths and it is easy to ask questions and get help and mentoring. I talked to several people who ran workshops and talks and they were very helpful. I received a lot of advice.

Lastly, the conference is great for networking. I have made a lot of connections with people. I usually meet people at conferences as I am very outgoing and friendly. However, this was by far the easiest conference to meet people. Everyone was so friendly and I left with 3 to 4 times the number of connections as compared to a typical conference.

I am used to going to conferences where I am one of a few women. This conference is mostly women and only a few men. That fact alone makes it an interesting experience, but the mirroring, mentoring, and networking are the key reasons why this conference more than any other is a must attend conference for every woman in computer science. Like I said, go atleast once!

Here is a great posting about specific events at Grace Hopper this year.
kd-PhD's Post on Grace Hopper

Lastly, my friends and I did a workshop at the conference on Origami and deltahedron. The name of the workshop was Computational Geometry with Origami, A Computer Science Circle. I have been learning how to run math circles for a few years but this was the first computer science circle I have done. More information about math circles can be found here:
The Math Circle
For the computer science circle at Grace Hopper, we made various deltahedron and explored the mathematical properties. It was a huge success and a personal milestone. 75 women and a few men showed up for the workshop. I'll write up the details of the material for this workshop in my next posting.

Grace Hopper Celebration Post 1

2009-09-29T10:21:00.000-07:00

Tonight I am going to the Grace Hopper Celebration of Women in Computing.
GHC09

I will blog about my experience. The first thing that is completely awesome about this conference is the CONNECT program. CONNECT

I submitted a profile and I listed out who I wanted to meet. Others did the same and then matches were sent to me. I have sent off a bunch of emails to the matches and a few people have already responded. So, I already have plans to meet someone tomorrow morning at registration. We are both interested in algorithms. This is already an amazing experience. I have never made friends before I actually hit the conferece! I predict that my facebook number goes up by at least 20 after this conference! I wish all conferences had a CONNECT program. It is very helpful when you are new to a conference.

Advice for Newbies at conferences

2009-09-26T10:22:00.000-07:00

I learned a lot going to the Graph Drawing Conference that I want to share. So, I am an expert in another field. I'm 38 years old and have worked in IT in industry since 1994. I know a lot of information. I have given talks and taught classes. I have been hounded by people wanting to get information about what I do so they can learn about it and advance their careers. I get emails from strangers asking for advice.

However, in the world of Theory of Computer Science, i am new. I went to the conference on Graph Drawing and I was pretty much lucky to understand parts of the talks. I was lucky to recognize certain words. But, for the most part, it was over my head. There was a part of me that wanted to leave. I'm busy and overtired and I need to do my homework!

However, I know better. I am a newbie to this world but i have the experience from other worlds that tells me what to do. Here is what i know is the right thing to do at a conference where you are a newbie.

1. Going to talks and just listening even if you are completely lost is part of the learning process. You will hear words and concepts and they will go into your head and sit there until years from now when you hear them again. It is all related. It will come up again.

2. Have something to say when you meet someone. Have an "elevator speech" ready. You are going to meet people at the conference. The first thing people tend to do is try to figure out who you are and what you are doing in your work. An elevator speech is a concept where if you are in an elevator with someone "important" that you have something to say prepared so that you make your pitch in that time. At a conference where you are a newbie, basically everyone is someone who knows more than you. When you meet someone, give your elevator speech in 2 mins and then ask them about themselves and have questions ready about the material. Try to get information from them. Be interested and engaged in the material.

3. Be respectful to yourself and others. At conferences we all get tired. Try to let things flow naturally and don't try to hard. Just relax. if you need a break from talking to people, then go walk outside or skip a talk break. It is better to be "on" when talking to others than to be checked out and half engaged when talking to others. Be respectful to yourself and get the rest for socializing that you need.

4. Help out. Ask the people running it if they need any help breaking things down or carrying things around. This is a great way to meet the conference organizers and the professors involved.

5. Follow up. So, after the conference, if a talk interested you then follow up on the material. Ask a professor for more info or a book to read. Email the people who did the talk for advice. Tell them you heard the talk and found it interesting but are a newbie and did not understand it. However, (and this is KEY) when you email someone ahead of you in any knowledge thing, be very short with your email. Often they are very busy and want to help but the emails people write are too filled with information for the person to digest. Make it short and to the point and VERY clear about what you need.

Hope this helps others. I also hope I can follow my own advice! Numbers 2, 3 and 5 are the hardest for me!

Graph Drawing Conference - Post 1

2009-09-23T03:20:00.000-07:00

I am attending the 17th International Symposium on Graph Drawing in Chicago this week.

Graph Drawing 2009

DePaul University is hosting the event.

GraphDrawing Organization

Basically, Graph Drawing is about the visualization of graphs. There is a mix of topics including making software to implement graph drawing and pure theory topics regarding what sorts of graphs can be drawn and why.

This topic is a cross over topic between math and computer science, so the conference sees a mix of both.

The first talk I will attend today is titled "Why are String Graphs so Beautiful?" by Janos Pach.

"In graph theory, a string graph is an intersection graph of curves in the plane; each curve is called a "string". Given a graph G, G is a string graph if and only if there exists a set of curves, or strings, drawn in the plane such that no three strings intersect at a single point and such that the graph having a vertex for each curve and an edge for each intersecting pair of curves is isomorphic to G." - Wikipedia

I will be blogging about the conference this week.

Exactly what math background is required for theory material?

2009-09-12T21:56:00.001-07:00

I am about dive into theory. I have taken the undergraduate intro to theory class and now I am going to take the graduate level classes. First stop is the Theory of Automata which begins Monday night. We will cover finite state automata/regular languages and pushdown automata/context-free languages. We are using Elaine Rich's text.

As a beginning theory student one thing that I find difficult is knowing exactly what math background I need in order to be strong in my theory classes. Elaine Rich has an appendix that provides a review of math material.

Some of that topics in the appendix:
Logic
Sets
Relations
Functions
Closures
Proof Techniques
Mathematical Induction
Pigeonhole Principle
Complexity of Algos

What classes was I supposed to take to learn the necessary mathematics needed for mastery of theory of computer science, I wonder? Do a lot of theory folks have a few undergrad mathematics classes on their transcript? It seems like logic, discrete math, set theory, combinatorics, and classes that demand proof writing are needed. This isn't a huge deal, but to take 4 undergrad math classes, including the calculus I,II,and III in addition to the other required undergrad computer science classes for your undergrad seems like a lot. Is this what most theory people have done before hitting the theory material at the masters level? What other math classes are required to master theory? Which are more important?

This is a question that keeps me up at night as I scramble to get the math background and level of sophistication required to figure out theory and be a strong student of the topic.

Theory of Computer Science - what is that?

2009-08-29T11:55:00.000-07:00

We all know that computers solve problems. However, computers can only solve certain kinds of problems. They can't solve all of our problems! Even if we have unlimited processor speed and memory, there are still problems that can not be solved by a computer.

The Theory of Computer Science is the study of problems and the solutions to problems. The first line of business is to provide a set of mathematical abstractions for classifying and solving problems.

Let me clarify what I mean by a mathematical abstraction. One example is a PDA (Pushdown Automaton). Another example is a FSM (Finite State Machine). Here is a picture of a FSM.

This FSM is taken from Elaine Rich's book, Automata, Computability, and Complexity. If you look at the picture you will see some circles. These are states. We have state 1, 2, and 3. Some of the circles are two circles in one. These are acceptance states. As input the FSM takes a string. For example, lets put abbba into the FSM. The start state is state 1, because it has an arrow pointing into it that does not come from another state. So, the input {a} causes us to stay at state 1 because the arrow leaving state 1 with an {a} on it points back to state 1. The next input is a {b}. This causes us to move to state 2. Then we enter two more {b's} causing us to loop back to state 2 a few times. Lastly, we enter a final {a}, which causes us to move to state 3. State 3 is not an accept state. Recall that only the states with two circles are accept states. So, this means that the FSM above does not accept the string abbba. What strings would it accept? What strings would it not accept? Basically, this FSM accepts any string that does not have the pattern {ba} in the string.

I want to return to my point that FSM's are mathematical abstractions. There are many of these sorts of mathematical abstractions introduced in the theory of computer science. I wanted to give you a concrete example, but my main point is that the theory of computer science gives readers a set of mathematical abstractions for classifying and solving problems. The FSM is one and their are others. TCS (Theory of Computer Science) splits problems into groups based on which mathematical abstraction can be used to solve the problem.

Each mathematical abstraction (also known as a machine) coresponds to a language class. A language class is a grouping of strings that are members of the language. So, in our example above, the language accepted by the FSM are all strings that do not have a {b} that is followed by an {a}. Examples of strings that are accepted are: aaaaaabbbbbbbb, ab, bbbbbb, ab and the empty string. The empty string is accepted because state 1 is an accept state. The strings aba, abbbbabbbb, bbbba, and ba are all rejected by the FSM above.

Machines and languages are in a hierachy. FSM's are the most basic. For more intense problems, a Pushdown Automaton must be used. For problems too complex for a pushdown automaton a Turing machine must be used. If a language can be accepted or decided by a certain machine (aka mathematical abstraction) then it is placed in that category of languages. Regular languages can be accepted by FSM's. Context-free languages can be accepted by Pushdown Automatons. Decidable languages can be decided by turing machine's that always halt. Lastly, Semidecidable languages can be semidecided by turing machine's that halt on any string from the language.

The main idea for this post is to introduce the topic of the Theory of Computer Science. In conclusion, problems are classified into groups. This is accomplished by encoding individual problems into specific languages of strings. Mathematical abstractions are created and the languages are either able to be accepted by the machine or not. If a problem is able to be accepted by a certain machine then the problem is classified in that category of languages. Finally, some problems can not be solved by any of the theoretical machines. It can be shown that if a problem can not be encoded into a language of strings that can be accepted by a turing machine then it can not be solved by a computer.

I will write more posts soon to explain these different machines and languages.

Note: I am reading Elaine Rich's book, Automata, Computability, and Complexity. These are some of my notes and thoughts after reading chapters one, two, and three. All credit goes to her book for these notes.

Theory of Computer Science and mathematics Blog

2009-08-19T12:15:00.000-07:00

I'm going to change the focus of this blog to Theory of Computer Science and math.

I am getting ready to start taking TCS classes exclusively and to really pour a lot of my time into learning the subject. So, i just want to focus my efforts there for now.

Cheers,
alex

C# Use delegates for Windows Form Communication

2009-08-05T14:25:00.000-07:00

Problem:
You have a main form and a secondary form. You want the secondary form to send information to the main form. However, the secondary form does not hold an instance to the main form.

Code for the secondary form:
public delegate void TextBoxDelegate(string strMessage);
public TextBoxDelegate TextBoxCallback;

private void button1_Click(object sender, EventArgs e)
{
TextBoxCallback(txtBoxOnSecondaryForm.Text);
}

Code for the main form:

private void button1_Click(object sender, EventArgs e)
{
Form2 formSecondary = new Form2();
formSecondary.TextBoxCallback = new Form2.TextBoxDelegate(this.WriteToTextBoxInMainForm);
formSecondary.Show();

}

private void WriteToTextBoxInMainForm(string strMessage)
{
this.txtBoxOnMainForm.Text = strMessage;
}

Netflix Prize Update

2009-08-05T06:26:00.001-07:00

New York Times Update on the Netflix Programming prize

Chicago CTA train Radio hacker busted

2009-08-04T10:09:00.000-07:00

Guy used a radio to transmit on the CTA

I graduated!

2009-06-12T15:01:00.001-07:00

I graduated from DePaul University with my masters in software engineering with a 3.75 GPA!!!!

HAPPY HAPPY DAY!!!!

next stop is the phd.... (I hope)

Grace Hopper Schedule is POSTED!

2009-05-27T17:30:00.000-07:00

WHEEE!!!!!!!!

I'm doing the - Computational Geometry Collaborative Learning with Origami – A
Computer Science Circle workshop with my friends at DePaul ACM-W.

Can't wait for this conference

GHC SCHEDULE

There is also some LGBT events. I'm really looking forward to this!

DataGridView - a simple example

2009-05-27T09:13:00.000-07:00

I usually need a simple datagrid that is populated from a callback instead of a database. Here is an example of how to do this.

1. Create two instances
private DataSet dsDataSet = new DataSet;
private DataTable dt;

2. In the constructor of your application initialize the data table
dt = dsDataSet.Tables.Add("Prices");

3. Create a function to create columns

public void setUpDataGridView()
{
DataColumn dc1 = new DataColumn();
dc1.ReadOnly = false;
dc1.ColumnName = "BidPrice";
dc1.DataType = typeof(string);
dt.Columns.Add(dc1);

DataColumn dc2 = new DataColumn();
dc2.ReadOnly = false;
dc2.ColumnName = "BidQty";
dc2.DataType = typeof(string);
dt.Columns.Add(dc2);

DataColumn dc3 = new DataColumn();
dc3.ReadOnly = false;
dc3.ColumnName = "AskPrice";
dc3.DataType = typeof(string);
dt.Columns.Add(dc3);

DataColumn dc4 = new DataColumn();
dc4.ReadOnly = false;
dc4.ColumnName = "AskQty";
dc4.DataType = typeof(string);
dt.Columns.Add(dc4);

dataGridView1.DataSource = dt;
}

4. In your callback for the event that gets the data add the rows

dt.Rows.Clear();
DataRow workRow = dt.NewRow();

workRow["BidPrice"] = stringBidPrice;
workRow["BidQty"] = stringBidQty;
workRow["AskPrice"] = stringAskPrice;
workRow["AskQty"] = stringAskQty;

dt.Rows.Add(workRow);

Mathematical Fiction

2009-04-26T20:09:00.001-07:00

This is a great site! It lists books that cover mathematical topics.

Mathematical Fiction

Bruce Hanna

2009-04-25T15:13:00.001-07:00

Bruce Hanna was one of my early science mentors. He was the best man at my parents wedding and he taught me about Astronomy as well as sailing. Bruce has passed away and he will be missed.

InsertionSort in Python

2009-04-05T08:07:00.000-07:00


A = [2,1,5,3,7,99,8]

def insertionsort(A):
    for j in range(1,len(A)):
        key = A[j]
        i = j - 1
        while i != -1 and key < A[i]:
            A[j]=A[i]
            i = i-1
    A[i+1] = key

insertionsort(A)
print(A)

Alan Turing was Gay!

2009-04-04T19:32:00.000-07:00

I just recently found out that Alan Turing was gay. I know for people who are not gay it is hard to understand why this is important, so let me try to explain. For some reason, it is important to have mirroring. This is where you see people like you in history or in present time that are successful and you identify with them. This helps a person to be motivated and to feel hopeful. I can only explain this from personal experience. I can't say that I understand it or could prove it was needed in any other way than personal testimony. However, the fact that Alan Turing is gay gives me a mirror as a gay person. I am proud to say that one of the most important computer scientists of all time was gay. Pretty amazing.

I found out by reading Neal Stephenson's Cryptonomicon which is a real good book! run to the bookstore if you haven't already heard of this book. Run don't walk!

PyCon 2009

2009-04-04T19:10:00.000-07:00

Pycon 2009 was a blast. The talks were great and I'm really excited about learning Python 3. I purchased Programming in Python 3 by Mark Summerfield and I'm installing 3 now on my linux laptop. I'm going to try out eclipse because i'm sick of idle. I will let you all know how it goes as I'm reading and experimenting.

I have a need to write a python tcp/ip multithreaded server for a reporting system. The server needs to report on the status of C#.NET clients.

I'm also taking Analysis of Algorithms right now so I'll be posting some python code for the algorithms i'll be coding up. Pretty exciting.

Happy Ada Lovelace Day

2009-03-24T19:41:00.000-07:00

Great Posting About Lady Lovelace

STATS.ORG

2009-03-19T11:24:00.000-07:00

Stats.org is a very interesting website. They have a newsletter as well. The group takes apart statistics used in the news and exposes flaws. This is very important work.
STATS.ORG

"rockstar developers" who are not good with people skills

2009-03-16T14:42:00.000-07:00

I agree with this article. I have worked in a lot of places were a really smart but crazy person was worshiped for his or her knowledge. However, this person was a problem for the organization and the team.

This is just a run of the mill BALL HOG problem. Highschool basketball teams don't put up with it so why should we?

Article: Are Quirky Developers Brilliant or Dangerous

Math Circle Chicago

2009-03-05T06:33:00.000-08:00

We have started the math circle Chicago. We have held a few workshops. Some for kids and some for adult women. We have done origami and mathematics as well as some discrete mathematics problems.

We are working on writing a math circle using number theory now. That will be offered summer 09.

Calculus is beautiful and What is math anyway?

2009-01-04T20:18:00.000-08:00

Calculus is just beautiful.

It is so simple.

It amazes me that I didn't think of it myself one day, because after it is shown to you it appears to be so obvious.

There must be other things about math that are so obvious that we do not currently see?

There must be dozens of directions of thought that are just there, like low hanging fruit waiting for someone to turn things upside down.

I've wondered for a long time: WHAT IS MATHEMATICS? I have also wondered if I could unlock the secrets to the universe if only I could understand math. I gave up on understanding the universe, but I think i found out what math is....

Math is just a way to express logical thought.

So, you create a game by making up rules and regulations. You say that in your game you are going to have a circle and that the circle is going to be placed on an x and y graph and that the radius of the circle is going to be 1. Then you play. You turn things upside down, sideways, and you shake it all about looking for more stuff. Hey - look if you stick a triangle on this circle, a right triangle, then you can say that the point is represented by x,y and x = cos theta and y = sin theta and then you make more rules and you make up objects ad definitions like radians and angles.

Then you change the game, you say ok - now we're on an x,y graph but we have different objects. These objects are vectors and in order to add them you must do this - and to multiply them you must do this.

So, you create objects and rules and playing fields and definitions and then you just look for things. You play the game and you make logical arguments and deductions and proofs and you look to see how one playing field and game compares to another. You just keep doing this and after thousands of years you have a lot of games and rules!

Oh - and of course you look for how these games can be used in real life. Like how trig can help you measure distances or how vectors can model how airplanes move in the sky.

That is what mathematics is....

Women and Math (and anyone in pressure situations)

2008-11-02T20:29:00.000-08:00

OK, I went to an amazing talk the other night at DePaul. The talk was by
Dr. Sian Beilock from U of Chicago

She studies the psychology of skilled performance as well as failure. Why would we fail when the stakes are high? Her talk was very scientific. Here is a summary:

1. We need "working memory" to solve problems. Working memory is basically RAM

2. If we're worrying then this takes up a lot of RAM and we can't solve the problem as fast or as correctly.

3. In the lab, it has been shown that just mentioning something like "we are running this test to study gender differences in mathematics performance"... or something like that can cause women's test scores in math to drop significantly.

The talk was really a lot more complicated than my summary. If you ever get a chance to here this professor give a talk, I would highly recommend it.

However, for me, this has really some practical hints. Basically, I am now noticing how much I worry and "ruminate" when trying to solve problems under pressure or even just in public. Getting rid of any "inner monologue" has become something I am working to diminish after hearing this talk. I always knew it was not helpful but I had no idea how much it really can hurt your problem solving results until I heard this talk.

This does not just effect women, but also it is the same thing (most likely) for anyone who has inner monologues that are unhelpful during pressure situations. What is unique to women is that just mentioning "gender differences" before a math test seems to create an unhelpful inner monologue that takes up much needed working memory.

C# team - gets kudos

2008-11-02T20:23:00.000-08:00

C# Team - Outstanding-Technical-Achievement

Face it, C#.NET is really enjoyable.... I enjoy it.

Famous Computer Scientists

2008-10-03T14:48:00.001-07:00

Thinking about famous programmers got me thinking about famous computer scientists.

Here are some lists of them:
Famous Computer Scientists - Wikipedia

Turing Award

ACM Fellows

Knuth Prize

Looking through the lists and the accomplishments gives one a good idea of what computer science really is....

Electroic Voting

2008-10-03T11:31:00.000-07:00

Wow. I watched a few electronic voting documentaries and the current system is in need of watchdogs and reform. Before watching the movies I had thought that people who were against electroic voting were just afraid of technology. However, not I understand that there is widespread incompentence and perhaps even fraud involved in these systems.

Here are some good links:

Black Box Voting

Andrew Apple's Blog

Best Movie I watched - Hacking Democracy

How to become a famous programmer

2008-09-29T08:07:00.000-07:00

This is a great article:
Famous-Programmers I ran into this while reading slashdot this morning. I loved the article. Here is a short summary:

About 50% of famous programmers got their fame from one project only.

Project Types:
Inventing a language or an algorithm
Writing a compiler, an application or tool, a game, an OS, or a book

There was also a very interesting part of the article that talked about how 97% of famous programmers are men. The article does a great job of defining famous too, which I liked.

There are 5 famous women:
1. Adele Goldberg
2. Grace Hopper
3. Ada Lovelace
4. Emily Short
5. Pamela Crossely
6. Roberta Williams
7. Danielle Bunten Barry

Since I have always wanted to be a famous programmer, I found this very interesting. Well, looks like the key is finding a really important project that adds a lot of value. hummmmm

List of famous software engineers

What to do when you are stuck in your coding?

2008-09-24T07:02:00.000-07:00

I asked all of my developer friends to help me make this list. It has really helped me already. This is a list of what to do when you’re stuck with your coding:

1. Find someone who you can talk to because discussion is key

2. Google it or use searchable documents and libraries like Safari Bookshelf
a. Pick keywords, error codes, messages
b. Search Google’s Web and groups for different combinations of key words
c. Stop this approach of searching after two hours

3. Books and pocket references

4. Forums and mailing lists, newsgroups – but monitor closely for responses and get back to responders with information quickly so they stay connected

5. Irc.freenode.net and ask on the channel

6. Email blog posters who might know

7. Local user groups

8. Place a rubber duck on your monitor and describe your problems to it. There's something magical about stating your problems aloud that makes the solution more clear.
http://c2.com/cgi/wiki?RubberDucking

9. Define the problem in detail because “Once a problem is described in sufficient detail, its solution is obvious” Kent Beck

10. Try approaching the problem from another angle

11. Take a break and come back to the problem

12. Compare the way you want to do it with a way that already works

13. Use tools, like Reflector in .NET to compare method and collect tools. Search for tools

14. Go back and read the documentation for the classes you are using

Election Systems - how to audit them?

2008-09-18T21:59:00.000-07:00

Here is the logic problem I'm working on at the moment.

I need to build an election system. An electronic election system.

How do I build an electronic voting system that the users can audit? I can't tie a vote to a person's ID or name due to privacy. I can't print out a copy of a paper ballot.

The only idea I have is to count the number of voters against the number of votes.

interesting problem....

Adult Women's Math Circle To meet again

2008-07-17T18:05:00.000-07:00

For this next group of meetings, we want to make it a series so that
we can stay with a topic for 5 sessions.

The dates we have in mind are all Saturday's from 1pm to 2pm.

1st meeting: Sept 6th
2nd meeting: Sept 20th
3rd meeting Oct 11th
4th meeting: Oct 25th
last meeting: Nov 8th

Suggested donation will be 5 to 25 dollars for this math circle.

We will soon put together more math circles for boys and girls together and also adult men and women as well as one for math teachers of elementary and also of highschool. These are to come. Please email me if you are interested.

Cheers,
alex

alexmcferron AT mac DOT com

Adult Women math circle chicago June 14th

2008-05-19T11:53:00.000-07:00

register at alexmcferron AT mac DOT com

Adult Women Math Circle
(ages 16 and up)

Free Workshop

This math circle workshop is designed for participants who enjoy math, or wonder if they could enjoy mathematics. It does not require any formal background in math. The only requirement is that everyone be friendly and collaborative. A lot of us love math but we may not have been exposed to the sorts of environments where mathematics was taught and explored in a way that kept us engaged. The math circle can fix all this. Attendees will work through a few math concepts or proofs using the math circle protocol. The group will work together to hopefully make a discovery or prove a theorem mostly on their own.

Saturday, June 14, 2008
1:00pm – 2:00pm
Columbia College Campus
619 S. Wabash, 2nd Floor
Chicago, IL 60605

To register for this event please email:
alexmcferron AT mac DOT com

Space is limited

5 ways to have fun with math

2008-05-18T15:26:00.000-07:00

Great post on how to have fun with mathematics!

PyCon 2008 - review of conference

2008-04-24T14:00:00.000-07:00

I recently went to PyCon 2008 in Chicago. I would recommend this conference. I am currently learning python and I found that at this conference there was a track of tutorials and talks aimed at the python beginner. I meet a lot of people and I had a pretty good time.

It is going to be in Chicago next year as well. If you are a developer and you live in Chicago, why not go and check out the conference while it is here in Chicago? It is not very expensive and it is a lot of fun.

Cheers,
alex

QuickFix Quick Start guide C#.NET VS2005

2008-04-24T13:50:00.001-07:00

I have created a short quick start guide for the QuickFix FIX protocol FIX ENGINE. The guide is part of a presentation I am giving at DePaul University tomorrow.

If you want a quick start guide for QuickFix (in the form of a powerpoint presentation), please go here:

QuickFix QuickStart Tutorial

Click on the link under Notes and tutorials that is called FIX PROTOCOL 101 - for Student Developers - includes a quickstart guide for QuickFix Programming using C# and VS2005

The presentation is in two parts and the second part is a tutorial that steps you through getting up and running with a QuickFix Acceptor and Initiator such that you are exchanging heartbeats.

Cheers,
alex

basics of web services in C#, VS 2005

2008-02-27T07:07:00.000-08:00

This post is dedicated to Jesse Liberty. I’ve been reading his books for a long time and I have to say, I love the way he breaks things down so simply. The sample code used in this simple tutorial is from his book called Programming ASP.NET.

There are two main parts to Web Services. First, create the web service. Second, consume the web service.

Requirements:
1. Have IIS installed on your windows machine
2. Visual Studio.NET 2005

Step one (Create a new Virtual Directory using IIS):
Open up Windows Explorer => right click on My Computer => choose Manage => open Services and Applications=> Open Internet Information Services=> Open Web Sites =>right click on Default Web Site and choose New Virtual Directory
Give the virtual directory a name: For this example, I am naming the Alias RequestAQuote
Give the virtual director a location: For this example, I have created a directory C:\RequestAQuote and I am mapping the virtual directory to this location. I am giving the permissions Read and Run scripts

Step two (Create the .asmx file that has the web services method stubs):
Open a text file and then save it with extension .asmx
This file I have named RequestAQuote.asmx
<%@ WebService Language="C#" Class="ProgAspNet.RequestAQuote" %>

using System;
using System.Web.Services;

namespace ProgAspNet
{
//This example can be found in Programming ASP.NET by Jesse Liberty and Dan Hurwitz
//I have modified this sample in trivial ways
public class RequestAQuote : System.Web.Services.WebService
{
// Construct and fill an array of stock symbols and price.
// Note: the stock prices are of 5/1/05
string[,] stocks =
{
{"MSFT","Microsoft","25.30"},
{"DELL","Dell computers", "34.83"},
{"HPQ","Hewlett Packard", "20.47"},
{"YHOO","Yahoo!", "34.50"},
{"GE","General ElectricDell computers", "36.20"},
{"IBM","International Business Machine","76.38"},
{"GM","General Motors", "26.68"},
{"F","Ford Motor Company", "9.11"}
};

[WebMethod]
public string GetAvailableStockNames()
{
string str = string.Empty;

for (int i = 0; i < stocks.GetLength(0); i++)
{

for (int x = 0; x < stocks.GetLength(1); x++)
{
str = str + "" + stocks[i, x];
}

str = str + "" + Environment.NewLine;
}

return str;
}

}
}

Step 4 (Go to the website created by this file and test methods):
http://localhost/RequestAQuote/RequestAQuote.asmx
You should get links to the available functions. Double click on them and test the methods.

Step 5 (Write a Client):
Click on References in VS2005 in the solution explorer. Add the Web reference URL http://localhost/RequestAQuote/RequestAQuote.asmx
Start up Visual Studio 2005 and start a new project. Create an ASP.NET Web Application. Navigate to the Default.aspx.cs file under Default.aspx to actually code the project.
In this section add this code:
namespace Requestquotes
{
public partial class _Default : System.Web.UI.Page
{
localhost.RequestAQuote request = new Requestquotes.localhost.RequestAQuote();

protected void Page_Load(object sender, EventArgs e)
{

}

protected void btnButton1_Click(object sender, EventArgs e)
{
string strOfAvailableNames = request.GetAvailableStockNames();
Label1.Text = strOfAvailableNames;

}

}
}
Then in the file named Default.aspx add the following code:

a. Create a button in asp so that when you click on it btnButton1_Click is called.

b. Create a label in asp so that all of the text from the web services method called by btnButton1_Click can output to this label

Here is a picture of this code

Basics of Web Services on windows using C#.NET VS2005

Math Circle Chicago

2008-02-20T07:20:00.000-08:00

I want to start a math circle in Chicago. If anyone is interested in this, please email me at hamcferron AT yahoo DOT com.

I've been reading Out of the Labyrinth: Setting Mathematics Free by Robert and Ellen Kaplan and the book is really great. Here is their website: http://www.themathcircle.org/

I think bringing the joy back to mathematics is really important for me personally. I remember being in school as a young person and I think there were a few beliefs that were not very helpful in learning and doing mathematics.

I thought that if I didn't understand the topic that I wasn't innately built for mathematics.

This caused me a lot of trouble, because I so desperately wanted to do mathematics that I would resist talking and asking questions because I feared being labeled as not innately built for mathematics. This was really not helpful because as I later learned, it is essential that you speak up when you don't understand something. What I have found to be true, is that when I'm first learning something I'm always lost and I need to talk about it to others. During this "FUZZY" period where I'm lost is when I'm learning. Just because it is "FUZZY" for me, does not mean that I innately wasn't built for mathematics. We are all innately built for mathematics. It is a myth that some of us can't think logically and can't understand math and that if you don't understand then you're not built to understand. Understanding is only in the want to understand. If a person wants to understand math then all they have to do is put the energy forth to think about it for some time. If they want it, it is there for them, but all mathematicians must go through not knowing before they know and when they don't know, it is imperative that they speak up and discuss their "fuzziness" in order to move to understanding. If you think that math, if it is fuzzy, is innately out of your reach, then this is not helpful in learning math but instead is a big gate that will keep you from the joy of mathematics forever. TEAR DOWN the gate and by all means have fun doing it!

Being comfortable with the fuzzy state that comes before the knowing/understanding state, is key to doing mathematics and computer science.

The math circle technique seems like a really fun way to get comfortable with this state in a non-competitive group enviornment.

I hope to do math circles in Chicago with adults and with kids. I hope to help bring joy back to math and smash all the unhelpful myths that have kept myself and others from daily math fun for long enough. Math is for everyone. Everyone can do it and it is awesome fun.

Cheers,
alex

Connect MySQL to a C#.NET Project using VS2005 on XP Professional

2008-02-18T08:55:00.000-08:00

Here is a helpful tutorial:
http://dev.mysql.com/tech-resources/articles/dotnet/#ODBC.NET

Here are my step-by-step instructions:

Set up the MySQL database

1. Download and install MySQL Community Server to your windows machine
http://dev.mysql.com/downloads/

2. Create a basic database for practice. Go to Start => MySQL => MySQL Command Line Client
http://dev.mysql.com/doc/refman/5.0/en/database-use.html

From this client create the basic db.
>CREATE DATABASE basicDB;
>USE basicDB;
>CREATE TABLE users (
LogonID VARCHAR(20) NOT NULL default '0',
Name VARCHAR(20) default null,
Password VARCHAR(20) default null,
LastLogon datetime default NULL,
PRIMARY KEY (LogonID));
>DESC users;
>INSERT INTO users (LogonID,Name,Password,LastLogon) VALUES ('amcferron','alex','12345678','2007-12-31');

3. Install the MySQL ODBC Driver-MyODBC 3.51
http://dev.mysql.com/downloads/connector/odbc/3.51.html#win32

4. On Windows XP Professional, go to Control Panal => Administrative Tools => Data Sources (ODBC)
Under the User DSN tab, choose ADD => scroll to the MySQL ODBC 3.51 Driver and click finish. A Login screen will pop up and you should fill out the following:
DataSourceName basicdb
Server localhost
User root
Password yourRootPasswordForSQLDB
Database => Here you should choose your database
once you see your database in the choices and you connect without issue, you can close this box down.

5. Open up a VS.NET 2005 project. Go to the toolbox and right click on the Data menu. Choose the "Choose Items..." option. Then under .net components add all of the components in the System.Data.ODBC namespace.
OdbcCommand
OdbcCommandBuilder
OdbcConnection
OdbcDataAdapter

also, in the code add using System.Data.Odbc;

6. Drag and Drop the ObdcDataAdapter from the toolbox to your Form and choose New Connection and fill out the form so that you are left with a tested connection to your database. This is pretty easy and now you are left with an odbcDataAdapter1 and an odbcConnection1 that can both be used

7. put the following code in your project. Put this code in a try catch block

this.odbcConnection1.Open();
string strSQL = "SELECT * FROM users";
OdbcCommand cmd = new OdbcCommand(strSQL);

cmd.Connection = odbcConnection1;

OdbcDataReader reader = cmd.ExecuteReader();

while (reader.Read()) {

Console.WriteLine("LoginID: " + reader.GetString(0));

}

reader.Close();

odbcConnection1.Close();

MathGrad Podcast

2007-10-31T13:17:00.000-07:00

I am loving listening to these podcasts!
http://www.mathgrad.com/

C#.NET Data Binding Basics

2007-10-19T11:19:00.001-07:00

http://www.devchix.com/2007/10/17/cnet-data-binding-basics/

VWAP (Volume Weighted Average Price) used in Algorithmic Trading

2007-10-10T06:53:00.000-07:00

The hard part is working out the alorithm that will be profitable using VWAP but calculating VWAP is really easy once you get the stream of prices and qty's into your program.

Basics of Unix Permissions

2007-10-07T19:46:00.001-07:00

this post is dedicated to my unix mentor Gloria who taught me this:

I'm on a development project right now that is using Linux and Python. It has been about 5 years since I have worked in Unix (unfortunatly!) and it has been about 2 years since I've programmed in Python (Sadly!) so, I need to get up to speed quick.

I'll have a series of posts about Unix, Python, and Bash Scripting:

This posting is the first of these postings and it covers the basics of unix permissions.

First, login, and then do a $ls -l to see your permissions

Two examples:
drwxrwxrwx
-rw-r--r--

The first letter d means that the permissions are for a directory. - means that the permissions are for a file.

the rest the letters should be broken up into three parts (user, group, and other)
rwx rwx rwx
rw- r-- r--

user = you
group = any group with rights to this file or directory
other = everyone

r=read
w=write
x=execute

to change the permissions of a file named textFile so that other(everyone) has execute rights, here is the command:
$chmod o+x textFile

to take away the permissions of a file named textFile so that other(everyone) has execute rights, here is the command:
$chmod o-x textFile

There is another way to think of permissions in unix. You could think of these permissions as on or off and represent them in your mind like this:

rwx, rwx, rwx = on on on, on on on, on on on
rw-, r--, r-- = on on off, on off off, on off off

now, since binary is good at representing on/off we can make a leap and change this to:
rwx, rwx, rwx = on on on, on on on, on on on = 111,111,111
rw-, r--, r-- = on on off, on off off, on off off = 110, 100, 100

now, since we're doing unix and being geeky is par for the course, we can change this representation to Octal numbers without missing a beat. So, now we have:
rwx, rwx, rwx = on on on, on on on, on on on = 111,111,111 = Octal 7, Octal 7, Octal 7 = 777
rw-, r--, r-- = on on off, on off off, on off off = 110, 100, 100 = Octal 6, Octal 4, Octal 4 =644

So, octal values that are relevant here:
000 = 0
001 = 1
010 = 2
011 = 3
100 = 4
101 = 5
110 = 6
111 = 7

So, the permissions can also be represented using Octal shorthand, but it only makes sense if you understand that 7 is octal 7 and you can translate octal 7 into binary and get 111 and that you understand that 111 means on on on and that on on on means rwx are all turned on.

Next posting of this series will be about BASH scripting basics.

Using graphics in C#.NET to explore slope fields

2007-08-31T12:12:00.000-07:00

Lately, I’ve been working on Calculus and the topic of slope fields has come up. Here is a good introduction to Slope Fields and why they’re important.
http://calculuslab.deltacollege.edu/ODE/7-1/7-1-0-h.html
So, I want to graph my own slope fields using C#.NET. I haven’t done any graphing applications in .NET yet but after doing some research I found that it is pretty easy. First, create a Visual Studio C# applications project. Then get an event into the application by going to the form properties, events section and double clicking on the Paint section to create a function called Form1_Paint. Then put code into the function to draw a line:

private void Form1_Paint(object sender, PaintEventArgs e)
{

Graphics g = e.Graphics;
Pen pn = new Pen(Color.Blue);
Point pt1 = new Point(30, 30);
Point pt2 = new Point(110, 100);
g.DrawLine(pn, pt1, pt2);

}

The graphics package for C#.NET is called GDI+ and the classes I’m using here are from System.Drawing.
I’m going to attempt to write a C#.NET application to draw and explore slope fields. I’ll put the code up on my website when I finish it.
Cheers,
Alex

Programming for number theory problems

2007-07-18T17:20:00.000-07:00

As I previously mentioned, I am reading A Friendly Introduction to Number Theory by Joseph H. Silverman. I want to highly recommend this book. It was recommended to me by Michael Kaplan from the Math Circle and he is right, this book is very accessible. I am reading chapters 1, 2, and 3 currently.

There are lots of problems that can highlight using the computer to make conjectures.

Some of my posts earlier showed that Excel most likely has an issue with large numbers and that was making me have false leads and results. I'm going to be looking at the following problem using C#.NET or perhaps Java.

This is exercise 1.4 from the book on page 11.
It is generally believed that infinitely many primes have the form N^2 + 1, although no one knows for sure.
(A) Do you think that there are infinitely many primes of the form:
(N^2)-1?
(N^2)-2?
(N^2)-3?
(N^2)-4?
(N^2)-a?

Which values of a do you think give infinitely many primes of the form (N^2)-a?

So, I'm going to move away from excel as I ran into problems. And I'm going to re-look at Conjectures about 3^n-1 and 3^n-2^n using the same problem.

For these problems, I'm just going to get the data output to a file and look at it.

Another problem from the book is 1.1 on page 11.
The first two numbers that are both squares and triangles are 1 and 36. Find the next one and, if possible, the one after that. Can you figure out an efficient way to find traingular-square numbers? Do you think there are infinitly many?

Here is some background to understand this problem:
Square numbers are (1,4,8,...) :
1^2 = 1
2^2 = 4
3^2 = 8
....

Traingular numbers are (1,3,6,10,...)
1
1+2 = 3
1+2+3 = 6
1+2+3+4 = 10

triangular numbers get their name from the design:
1 =
.

3 =
.
. .

6 =
.
. .
. . .

and if you understnd the pattern, you can see that the next row would be 4 dots

Well, for this problem, I am also going to write a computer program. However, this one will compare two lists that I will create. I try to create a list of 1000 triangular numbers and 1000 square numbers. Then I will compare them.

SO, this brings up some computer science questions.
1) What algorithm is the most efficient for comparing two lists of 1000 numbers each?
2) What data structure is the best to hold these lists in java or C#.NET?
3) What language is best for this sort of a thing? C#, java, python, maple?

I will be thinking about these things over the next week and I'll report back. If anyone has any ideas or comments, please post!

Thanks so much for your comments.

cheers,
alex

Number Theory Introduction

2007-06-21T17:26:00.000-07:00

Number Theory is the study of the integers. Integers are ...,-3,-2,-1,0,1,2,3,...
and are often noted as capital Z.

I'm reading three books on the topic this summer.
1) The Theory of Numbers by Niven, Zuckerman, and Montgomery
2) A Friendly Introduction to Number Theory by Silverman
3) The Higher Arithmetic by Davenport

The part I am reading about right now is all about divisibility.

So, what does it mean for a number to divide another number?

If we divide 100 by 25, then another way to think about is to imagine that we have 100 balls and we want to organize all 100 balls into piles of exactly 25 balls each. If we do this, how many piles of 25 will we have when we are done?

we can also think about dividing 100 by 25 by writing it as a fraction. 100/25 is 4. If we turn this fraction over and divide 25 by 100 then we get .25

25/100 = .25 which is not an integer but rather a decimal number. Anyway, what this means is we have 25 balls and we want to make 100 piles. If we make 100 piles then each pile can only have .25 of a ball in it.

Here is an example of a divisibility theorem from number theory:

if a divides b then a divides bc for any integer c

proof:
if a divides b then there is a number x such that ax = b. This is the definition of divisiblity.

lets take ax = b and multiply both sides by c
to get....

axc = bc

now, by the definition of divisiblity if ax = b where x is any integer, then a divides b.

So, let y = xc
we know that y is also an integer so ay = bc and so by definition, a divides bc

proved!

There are many more proofs like this one in number theory.

Experimental Mathematics

2007-05-25T13:55:00.000-07:00

In one of my math magazines "Focus" there is a very intersting article about Experimental Mathematics. This is what I am trying to do. The article is an interview with Doron Zeilberger. Ironically, I just went to a talk by him the other day at DePaul. Great speaker: very loud, he would scream at you and then laugh that he was waking you up with the loud screaming. very funny and also slightly alarming ;)

ok. this article really has my interest. Here are the key take-aways for me from the interview:

1. Think about using computers and algorithms to do mathematics quickly and efficiently

2. programming gives you insight and understanding (re: mathematics)

3. He finds examples to work with in combinatorics and the theory of special functions. These examples can be used to train the computer to discover conjectures. This is experimental mathematics.

4. Trying to prove the conjectures without any human intervention is called Automatic Theorem Proving. Very interesting!

5. the Wilf-Zeilberger algorithmic proof theory is contained in all computer algebra systems and it is a collection of algorithms that can discover, and then prove, binomial coefficient "n choose k" counts the number of k-element subsets of an n-element set.

4. There is a journal by the name Experiential Mathematics and some books coming out. I'll keep my eye on them.

Conjectures about 3^n-1 and 3^n-2^n

2007-05-10T17:53:00.000-07:00

I am making some educated guesses (conjectures) about 3^n-1 and 3^n-2^2 based on making a table in excel and looking for patterns. When are these numbers prime?

Mathematicians look for patterns and then make conjectures which then they try to prove. So, this is what I am doing:

Conjectures about 3^n-1
1) This result is always even and therefore never prime for n > 1

2) After n=32 the result will always end in zero

3) After n=32 the number of zeros will typically increase so that for large numbers of n there will be a lot of zeros. The ratio of numbers other than zero to zero will decrease as n grows.
For n = 66
result = 30903154382632600000000000000000

For n = 200
result = 265613988875875000000000000000000000000000000000000000000000000000000000000000000000000000000000

Conjectures about 3^n-2^n
1) for n > 31 the result will always end in a zero and not be prime

2) The numbers of zeros is increasing with n increasing

Also, I still need to look at the values left here because they appear prime or possibly prime. I need to write a computer program to check that they're prime. However, all other numbers resulting from 3^n-2^n proved to not be prime.

Conjectures

2007-05-09T08:11:00.000-07:00

So, I'm reading How To Prove It, by Daniel J. Velleman as I'm on a quest right now to work on proofs everyday. In then introduction, he says that mathematicians look for patterns. When you see a pattern you can call it a conjecture. A conjecture is just an educated guess. So, for example he gives an exercise to make some conjectures about the values of n for which 3^n-1 is prime or the values of n for which (3^n) - (2^n) is prime.

Step one of this is to make a table of results and then look for a pattern:

I made this table using excel. I'm going to run it for more numbers and over the next day or so, I'm going to try to come up with some conjectures about the data and then try to prove the conjectures. Theorems are conjectures that have been proven.

cheers,
alex

Induction

2007-05-07T08:24:00.000-07:00

Prove If x>=4 THEN 2^x >= x^2

Induction was an easy way to prove this one!

I need to figure out how to get math text into this blog. I'll work on learning how to do that.

Prove If x>=4 THEN 2^x >= x^2

2007-05-02T07:29:00.000-07:00

Currently, I'm working to prove If x>=4 THEN 2^x >= x^2

I can see that it is obviously true, but how to prove this. My first thought was to use induction.

I'll be thinking about this problem for today. It is from a book I am reading: Automata Theory, Languages, and Computation by Hopcroft, Motwani, and Ullman

54th Midwest Theory Day

2007-04-30T03:28:00.000-07:00

On saturday I want to the 54th Midwest Theory Day conference.

http://facweb.cs.depaul.edu/jrogers/MTD/

Here were the key takaways for me:

1. Paul Rothemund's work on algorithmic self-assembly. I was told that if you want to learn more about this, then reading Paul's PHD thesis is the place to start.

2. Arthur - Merlin Protocol - an interactive proof system
http://en.wikipedia.org/wiki/MA_(complexity)

3. Integer programming, Linear programming, dynamic programming

4. sigma 2 machines

5. One method of problem solving that I noticed was that people at the conference would turn a problem they didn't know how to solve into a problem they did know how to solve. The would show that the open problem was just like another problen we already knew about.

Mathematical Abstraction

2007-04-27T05:31:00.000-07:00

I am reading A Very Short Introduction to Mathematics by Tim Gowers. In there he talks about how is is better to think abstractly about math. Think of math as a chess game. Think of the mathematical objects as game pieces (rooks, knights, queens) - these pieces have certain rules of behavior. The queen can move in any direction and number of squares. The pawn can move one space. Integers must follow certain behavior rules.

So, it is better to follow the rules of the game and treat the game as an abstraction then to think sit down and get caught up in "what is an integer", "what is meant by infinity", "how can something go to 0 an infinite number of times". Instead just treat it as a box. These are the rules. These are the objects. Given this situation, what is true?

This is the best way to think about math, according to Tim Gowers.

I have to say that this idea has helped me a lot. I am definitely one of those people who has never been comfortable with thinking of math abstractly. I have wanted to know how it all fit and how it worked. I wanted to see and completely be able to grab hold of 12 dimensions. But I give up. I do see how this has made math very hard for me.

Cheer Tim Gowers!

Infinite number of twin primes

2007-04-25T07:05:00.000-07:00

OK. I'm trying to prove that there are an infinite number of twin primes.

I have no idea what I'm doing.

I'll post back in a few days when i think of something regarding this issue.

If anyone has any suggestions, please let me know.

I'll start with assuming that there are a finite number of twin primes and attempt to find a contradiction. Seems reasonable.

I solved this proof on my own!

2007-04-24T06:31:00.000-07:00

So, last night, at a coffee shop, I just sat down and the answer was so clear! I was looking at the case for n=5 but the general case was pretty obvious after understanding it for n=5

The theorem to prove: For every positive integer n, there is a sequence of n consecutive positive integers containing no primes.

I gave myself a hint:
Suppose n is a positive integer. Let x = (n + 1)! +2
Show that none of the numbersxx+1x+2x+3......x + (n-1)is prime.

Then I wrote this out and the answer was so clear:
( 6 x 5 x 4 x 3 x 2 x 1 ) + 2
( 6 x 5 x 4 x 3 x 2 x 1 ) + 2 + 1
( 6 x 5 x 4 x 3 x 2 x 1 ) + 2 + 2
( 6 x 5 x 4 x 3 x 2 x 1 ) + 2 + 3
( 6 x 5 x 4 x 3 x 2 x 1 ) + 2 + 4

( 6 x 5 x 4 x 3 x 2 x 1 ) + 2 - will always be divisible by 2
( 6 x 5 x 4 x 3 x 2 x 1 ) + 3 - will always be divisible by 3
( 6 x 5 x 4 x 3 x 2 x 1 ) + 4 - will always be divisible by 4
( 6 x 5 x 4 x 3 x 2 x 1 ) + 5 - will always be divisible by 5
( 6 x 5 x 4 x 3 x 2 x 1 ) + 6 - will always be divisible by 6

When I looked at the book it shows it like this which is even clearer. It factors out the number that this number is divisible by thus proving that this number is not prime.
2 ( 6 x 5 x 4 x 3 x 1 ) + 1
3 ( 6 x 5 x 4 x 2 x 1 ) + 1

The next theorem I will work on is one that no one has yet solved. But why not, I'll give it a shot. Show that there are an infinite number of twin primes.

Why does x = (n+1)! =2 produce n consecutive non-prime numbers?

2007-04-23T06:03:00.000-07:00

I am going to try working with the example of n=5 to see if I can figure out why this is true in the general case:

Suppose n is a positive integer. Let x = (n + 1)! +2
Show that none of the numbers x, x+1, x+2, x+3, ......x + (n-1) is prime.

So, what about this for the case of n=5 insures that non-prime numbers result?
( 6 x 5 x 4 x 3 x 2 x 1 ) + 2
( 6 x 5 x 4 x 3 x 2 x 1 ) + 2 + 1
( 6 x 5 x 4 x 3 x 2 x 1 ) + 2 + 2
( 6 x 5 x 4 x 3 x 2 x 1 ) + 2 + 3
( 6 x 5 x 4 x 3 x 2 x 1 ) + 2 + 4

( 3 x 2 x 5 x 2 x 2 x 3 x 2 x 1 ) + 2
( 3 x 2 x 5 x 2 x 2 x 3 x 2 x 1 ) + 2 + 1
(3 x 2 x 5 x 2 x 2 x 3 x 2 x 1 ) + 2 + 2
( 3 x 2 x 5 x 2 x 2 x 3 x 2 x 1 ) + 2 + 3
( 3 x 2 x 5 x 2 x 2 x 3 x 2 x 1 ) + 2 + 4

This number ( 3 x 2 x 5 x 2 x 2 x 3 x 2 x 1 ) which is (n+1)! in the case of n = 5 is where I will turn my attention today while thinking about how to prove this theorem.

cheers,
alex

Long stretches between primes

2007-04-22T09:25:00.000-07:00

Theorem: For every positive integer n, there is a sequence of n consecutive positive integers containing no primes.

I felt I needed a hint, so I read a bit more of the proof:

Suppose n is a positive integer. Let x = (n + 1)! +2
Show that none of the numbers
x
x+1
x+2
x+3
......
x + (n-1)
is prime.

I wrote a test case:
n = 5
x = (5+1)!+2 = 722

so the 5 numbers that aren't prime
1. 722
2. 723 - is 3 * 241 (not-prime)
3. 724
4. 725
5.726

So, why on earth would this work?
Why is it true? Is it true for all cases?
How can I prove it?
This is going to be interesting!

Philosophical side note:
It is pretty amazing to sit and think about no matter how big n is that this theorem, once proved, will show that there is a consecutive list of numbers as big as n that are not prime. This makes me think of the universe and how at some point we have got to deal with the contradiction: Can the universe go on forever? Or can it end? If it ends, what is on the other side? I feel like neither one of these answers can be correct (1. it ends 2. it never ends) and that there is some fundamental problem with the way we see the universe.

Well, I'll leave the big question on the universe to God and I'll just worry about proving that there exists a long stretch of n consecutive numbers in our integer number system, which luckily can go on forever without any contradictions :)

cheers,
alex

Proof that shows why we have an infinite number of primes

2007-04-21T14:36:00.000-07:00

Say there are a finite number of primes so that we could list them out in a list:
p1, p2, p3, ....pn

now, lets create another number named m:
m = p1*p2*p3*....pn + 1

if m was a prime number it would have to be in the list

however, it can't be in the list because it is bigger than anything in the list so m isn't prime

m can't be divided by any number in the list (because it would leave a remainder of 1

all non-prime numbers can be divided by a prime number though as all non-prime numbers break down into primes

this is a contradiction so the assumption must be false and there must be an infinite number of primes

BRILLANT!

Observations about this proof:

1. If you had a list of all of the primes up to a point (2,3,5,7,...,n) and you multiplied them together and added 1, I believe you would always get a prime, but it wouldn't be the next prime. It would be much larger than the next prime.

2. if you have a list of primes (2,7) then m = 15 and 15 can be decomposed into primes 3 and 5 so this algorithm seems to only generate primes (for sure) if you have a complete list of all primes up to a point and then add 1.

Here is the next theorem To Prove:
For every positive integer n, there is a sequence of n consecutive positive integers containing no primes.

How do we know there are infinitely many primes?

2007-04-20T07:09:00.000-07:00

So, while on the EL last night and this morning I thought about why there are infinitely many prime numbers. Why is this true? I’m trying to figure it out on my own first before I read the answer.

I have a lot of questions about primes now to explore:

1. Is there a relationship between one prime and the next prime? If there were this relationship, then we could create an algorithm that will generate new ones from the last one. However, I think there is not a relationship like this. I also think this relates to cryptography algorithms.

2. How do we generate large prime numbers? How do we find them? I wonder if we have to use a large super computer and I bet we do. How do we know a large number is prime?

3. I wonder what kind of program I could write to generate primes and how many I could find and how long it would take. I will try to write one and see what happens. The only idea I have is the brute force method. I’ll write that and then see if I can find tricks others have found on the internet.

4. Finding primes and taking an integer and decomposing it into prime numbers are related. If we could write a computer program to quickly factor integers into prime numbers then we would quickly know if that number was prime or not. Again, I bet we can’t do this.

Some sites I want to read and digest:
http://en.wikipedia.org/wiki/Integer_factorization
http://en.wikipedia.org/wiki/Factorization#Prime_factorization_of_an_integer
http://en.wikipedia.org/wiki/Prime_number

5. Is there a pattern between primes or is it totally randomly dispersed? I think there is no pattern.

6. I have some questions about odd and even numbers to explore. Like if you multiply two odds what happens, two evens, and odd and an even? Are there patterns here like there are with adding?

All of this is a lot of interesting stuff, but I’m still at a loss for why it is true that there are an infinite number of primes! I am very curious now to see the proof but I’ll try to figure it out on my own for longer as it will make reading the proof even more enjoyable. I’m in such awe for these proofs! How did these people come up with these proofs? Amazing stuff.

Proofs

2007-04-19T12:28:00.000-07:00

I want to learn math and computer science. I want to meet others interested in learning these topics. So, I'm starting a blog in hopes of making friends. The whole point of this blog for me is to make friends and to have fun.

Right now I am reading How To Prove It by Daniel J. Velleman, and I'm on the introduction. I'm trying to work a bit each day on doing proofs, mostly I'm working on proofs while riding the CTA train in chicago. Well, if I fall asleep so be it, but i first try to work on proofs.

The first chapter has some definitions:
1. prime numbers - can not be written as the product of two smaller positive integers
2. conjecture - a guess, an educated guess
3. Theorem - a conjecture that has been proven
4. mersenne primes - prime numbers of the form 2^n-1
5. twin primes - primes that are two away from each other (examples: 5,7 and 29,31)
6. perfect numbers - n is perfect if n equals the sum of the smaller positive integers that divide n (examples: 6 because 1+2+3 = 6 and 28 because 1+2+4+7+14=28)

I'm going to think about this Conjecture in the book and try to prove it myself before reading the answer:
Conjecture 2: Suppose n is an integer larger than 1 and n is not prime. Then 2^n-1 is not prime.

I'm also going to think about this Theorem from the book and try to prove it myself before reading the anser:
Theorem 3: There are infinitely many prime numbers.

I really have no idea how to prove these two things. Without looking at the book it is hard to know where to even begin thinking of these two problems.