Matrix representation of an ellipse

Its nice to know how we can represent an ellipse and then an ellipsoid in the form of matrix. Such matrix represenation will help us develop various concepts of normal distribution while trying to fit an ellipse around datapoints. I just put this link for reference.

 http://www.cs.mtu.edu/~shene/COURSES/cs3621/NOTES/geometry/simple.html

AMAZING SUCCESS !! The 4 Day plan

Hey all!!! , It was an awesome experience working with python. My 4 day stint was just too good to describe. I started with no knowledge of object oriented programming and python and since my lat post on 22 , today i am done creating the game!!! this is how it looks now.

It has 3 manual controlled players and 3 computer controlled ones. Every thing is object orienter with classes for ball,goal,players,stadium,music and what not!! Wooh .. I am so inspired by the ease in which you can develop games using python and the pygame framework

I am so excited that i have just spend around 90$ to buy a space and a domain names “pyguru.com” to start writing about pygames and its development (Also the language python) . That tells how good the experience was !!!

I would surely put the code out here for others to use and add on the fun also EXE of the game for people who just want to play it!!

All this after my finals week , that is after dec 7th .

Madan

4 Days to Python Gaming

Hi all, its been long time as ever since I’ve posted stuff. But here I really sense some good bunch of posts that would come along!! My term is going to end and guess what!!! Finals week is so near and guess what, time ti submit project!! . Ha…. that reminds me of my oop project.

Well i really donot know any oop programming yet . I know a good amount of C but that will definitely not help. I think its mow time to learn the OOP!!!. I know to work with class and some inheritance with some knowledge in c++. But I will not be ale to do a project with C++  either.

Well, then what is the way out! ? PYTHON … is it easy ? I really donot know . Why ? Cos I don’t know python!!! . Then ?  that’s the catch… Iam starting to learn python at this moment.WordPress time stamp will note it down for me. And what is the goal ? Well  to create a small 3 player 2D soccer game in python using pygame framework and libraries.

Cooooooool!!  so here i am going to inaugurate my stint for the next four days (missing all the thanksgiving action ) doing my project. I plan to document the codes and files as i write so that this can serve as one small chapter of Python learnin too!! (Cool a new category introduced into my blog yeppieeee !!)

so lets begin “4 Days to Python”

Gud Luck (Cheering myself up!!)

Principal Component Analysis

I was just looking for some information on ISOMAP . I had then hit by the terms PCA and MDA a multiple times that i decided to give it a good glance . Though i am looking for somehting on machine learning , currently i am into a work with one of my professors who wants to implement AI into some kind of pattern recognition in flow cytometry.

So I have started looking at these topics and i am really amazed at the statistics involved in pattern recognition. So i just give a link here to a tutorial that provides a very clear explanation about PCA method of reduction of high dimentional data.

THE LINK
http://csnet.otago.ac.nz/cosc453/student_tutorials/principal_components.pdf

Hope it amuses some of you too

-Madan

Last week ka assignment

 

Last week was fun writing a program of a vacuum cleaning agent. Though I had done quite a good amount of work in writing such robotics code, this was a bit different. I had a chance to develop my first object oriented design.Well not really object oriented tough , I developed an agent that was random. It was a pleasure watching my program display how my robot randomly cleaned a 10×10 arena of dist.

I dont know how far this would be known to a good C programmer but to me it was new.I alway thought that the rand() function in C would generate a random number. I was to generate some random number based on which my vaccum cleaning agent will move in the arena.I was happy with the first run when my agent did generatenrandom output.But the second time I run the same code, I felt something redundant.I felt my program was generating the random number in the same sequence all the time. What’s the point!!

The way out to generate random numbers using rand() function is to change the value of srand(a) every time. Thus if you generate a random value to reaplace a and then again execute rand() you’l generate a good random number. But by logic even that will repeat thought the cycle, but its too largr to be percieved by a small program.

The code goes like :
int a,random_number;
a = rand();
srand(a);
random_number = rand();

Well I will post my code for the robot and it looks really pretty to watch the unpredictable behavior of an agent program.There must be some other way too.Rushing towards my submision I felt this was a good alternative.

Hi!! I’m back

Well its quite some time that I did not post anything on this blog of mine. Its a month since i came to Oregon state university for my masters and I really did not get the time I used to have back in India to maintain this blog.

This blog started with an idea to give away working circuits and assistance for works on robotics in general and specifically on some autonomous robotics. I had put a post on micromouse which really crowds in with a lot of traffic. I am planning to put the code aswell here for once so that a lot of people can use it as a study aid.

This blog further will proceed deeper into the field of artificial intelligence and probably this blog would change its course from a more basic help tool for beginners to probably some reference for my fellow grad students and others. I am new to AI too and I hope future posts will see myself grow from a beginner to pro in AI!!!

Madan

 

 

Micromouse contest – on the way!!!!

This was on my mailbox and i just felt the need to keep my readers aware of it.

Welcome to MindSpark 07! MindSpark is the annual technical festival of College of Engineering Pune. MindSpark will be conducted this year on 5th, 6th and 7th October. We have a host of events lined up as part of MindSpark including Robotics, Paper Presentation, Business Plan contest, programming contests, Contraptions and Circuit design competitions. COEP is proud to associate with IITBombay Techfest in their Nexus initiative.

The Robotics event has three competitions - Micromouse (the standard autonomous robot competition), Dogfight (Manual robots slug it out against each other in a pick-and-place competition) and IITB Techfest Nexus. The preliminary round for Techfest Vertigo will be held at COEP under Nexus, the winner gaining a direct entry at the IITB Techfest in January.

The prize money for Micromouse and Dogfight is a cool total of Rs.70,000 (20k + 15k for each event). Accomodation facilities will also be provided on the college campus with a nominal fee of Rs.150 per participant for three days. Online registrations for the competitions has started. Register yourself as early as possible.

See you at MindSpark!

for more details -
www.mind-spark.org
www.robotics.mind-spark.org

Contact – Vineet 09823743030 (Co-ordinator, Robotics)

My friend pratap is one of the co-ordinators of this event, and he is a very friendly person so i take the liberty of posting his contact too.Guys have fun participating!!!

Pratap Tokekar
Co-ordinator, Events
MindSpark 07
COEP
09423234455

Php to Excel

This is one sweet code to export your variables and pass it on to a downloadable excel file. As of now i am working on an resume maintenance project and that needs this aspect. I googled for the simplest and efficient code.

I use a wamp localhost and faced warnings with all classes and codes that use the fopen(xls://FILENAME) format. This particular code was so cool enough to not read and open any existing file but just provide a  new file that you’ll name at runtime and download.

Its  more like writing the file on flyby!!

If you were one among those who googled for excel to php/php to excel/php write excel files/write excel files in php  and came here, trust me its a standalone simple code below. Just copy paste and it will start working.

<?php
$line1=”ID\tProduct\tColor\tSales\t”;
$line2=”1\tPrinter\tGrey\t13\t”;
$line3=”2\tCD\tBlue\t15\t”;
$line4=”3\tDVD\tRed\t7\t”;
$line5=”4\tMonitor\tGreen\t4\t”;
$line6=”5\tTelephone\tBlack\t2\t”;
$data=”$line1\n$line2\n$line3\n$line4\n$line5\n$line6\n”;

header(”Content-type: application/x-msdownload”);
header(”Content-Disposition: attachment; filename=extraction.xls”);
header(”Pragma: no-cache”);
header(”Expires: 0″);
print “$header\n$data”;

?>

The code is pretty self explanatory with /t for column break and \n for line break.

Cya
Madan

Heard of Multiplexing?? what about Charlieplexing!

Well as you know multiplexing is a method to communicate more data with a lesser existing channel or time. Just to sound similar because of a analogy char…plexin is called so.

 

Charlieplexing is method to drive more number of LED’s from very less number of pins. Now there are loads of pages talking about this method on the internet. I found most of the very vague. I have tried to assimilate them together here on my page. So here it goes,

 

It is a method of driving many number of Led’s with lesser number of drive pins. One simple analogy being, if you wanted to drive 6 Leds in some sequence how many microcontroller pins would you want?You would say 6. Why just you!! most would say 6.

 

These days we have 40 Pin microcontrollers which makes the value of each I/O pin really less. But first let me explain you the context. in small series of microcontrllers which would just have 5 pins, it is impossible to drive 6 Led’s with our concept of using a single pin for one LED.

 

Well i can hear you say that you can use a multiplexer!! a 3 to 7 Mux or something?? well i would say you are not wrong, charplieplexing provides an amazing method when in goes to huge numbers.

Concept:

Say we have 3 pins A,B,C of a microcontrollers. We can connect 6 LED’s in a combination such that,

 

When A=5v , B=0v we’l have LED1 glowing and all other LED’s off
When A=0v, B=5v we’l have LED2 glowing and all other LED’s off

 

Pair LED1 and LED2 are a complimentary pair. Similarly we can have 3 such pairs and control all 6 led’s form 3 pins.

 

I am very sure you are not clear about the concept.. Well you must read this to understand the concept completely. Link goes to instructables

Swimming Snake Robot !!

Here and there at times i post few videos from you tube. even if they are my own videos i do host them to youtube and embed here in wp. Well just browsing i found this video of a swimming snake robot. I have seen many beam based land robots that twist and turn around to move. This one is a masterpiece. It swims in the water with elegance and absolutely gentle . The video doesnt give a complete design details of the bot, but the author does explain and show few things on the videos. I just mean to give my blog readers some new input of the way robotics is proceeding. Have a look.

 

 

Madan