pradeepgowda.com

Attractive Charts with Open Flash Charts and Django

2009-04-16T01:52:56-05:00

On request from a user, I've put together a sample django app that uses PyOFC2 to render charts in web browsers using Open Flash Charts 2.

The django+pyofc2 demo code can be downloaded from github.

Using PyOFC2 with Django

Download Open Flash Chart 2
Download and install PyOFC2
Download SWFObject and put the files in your static media directory
Add references to the SWFObject files and open-flash-chart.swf file in the header section. See templates/index.html for details
Create a view to serve the json data from. See demoapp/views.py
Configure urls.py to map the view to the url endpoint.

Adding OpenID to your website

2009-04-03T22:44:00-05:00

With the advent of openid providers like Clickpass , having your own OpenID has become very easy. Services like clickpass use the APIs provided by popular service providers like Yahoo, Google to enable you to use those accounts as openids.

However, nothing beats having your website or blog act as your OpenID. After all, btbytes.com is shorter than my.yahoo.com/btbytes.

To make your website a OpenID “provider”, you need two files and 5 minutes.

Download phpMyID .
Edit MyID.config.php
Create a md5 hashed password : <pre>$ echo -n 'username:realm:password' | openssl md5 </pre>
Upload the files to your website root directory.
Add these two lines to head section of your frontpage (or the header template of your blog software).

<link rel="openid.server" href="http://mysite.com/MyID.config.php"> <link rel="openid.delegate" href="http://mysite.com/MyID.config.php">

Thats it.

To test your setup, go to any openID enabled commenting system (eg: LiveJournal blogs) and enter your website’s URL. The site you are on will make a request to your website, asking it to verify you. Your site will ask you for username and password. If the user name and password is correct, your site will in turn send a message to the requesting site saying that you are the genuine stuff.

Once you have logged into into your OpenID provider, as long you don’t clear the browser cache, you should be able to just enter your website into any OpenID box and be automatically logged in. This is the major advantage over
having to maintain a login for every site.

Year 2009 prospects

2009-03-22T23:28:35-05:00

I am taking a graduate level course on Computational Intelligence at Purdue school of engineering/IUPUI. With this course, my long standing desire to study subjects related to genetic algorithms, machine learning etc has come true.

My first introduction to genetic algorithms was from the Nov 1996(?) issue of Resonance, a science journal from the Indian Academy of Sciences.
The cleverness of GA prompted me to study it along with Neural Networks (esp. Self Organizing Neural maps) between 2000-2002. Between 2002 and 2003 I, as part my work at a (now defunct) startup, used Naive Bayes, Decision Trees(J48), k-Nearest Neighbours etc to improve credit card defaulter prediction in retail banking. I also used the Fuzzy Logic module from DataEngine package to build a root cause analysis package for a power plant. My well thumbed and pencilled copy of Data mining by Han and Kamber is a prized possession from that time.

After that, the study of machine learning and data-mining algorithms continued to be a hobby. I studied data envelopment analysis and learned to solve DEA problems using the GLPK package on Linux in 2006-7.

After coming to US in 2008, I wanted to make use of the proximity to IUPUI campus to study further. The first course I took was ECE 536 – Computational Intelligence taught by Prof. Eberhart. He is one of the pioneers of the Particle Swarm Optimisation method. I’ve found much satisfaction in attending the classes and doing assignments. I finally managed to use my fledgling TeX skills (via ConTeXt) to do assignments.

In the coming months, I have a plan of doing self-study in mathematics refreshing pre-calculus trigonometry and calculus. The ability to read a page full of mathematics and understand it is important. The programmer in me pushes me to write code for all the neat algorithms I learn and discover. But, I realise that producing code should be a side effect of deep learning and solving problems, at least till I get a good grip of the algorithm fundamentals.

At work, I’m getting to do a lot of Python coding along with Flex3, Erlang and C. Lua looks to be an interesting and easy way to provide scripting capabilities to applications. I’m attending PyCon 2009 at Chicago. I’m looking forward to see and hear from all the smart python people.

This site went through another styling change. But, more importantly, I have realised the utility of having a constantly updated public notebook of sorts. Once I took away blog format, and all its attendant bells and whistles, I started editing and improving what was already there. I have added a few new pages as starting points for later addition and editing. Between the twitters and delicious, the ego-blogging and the link-blogging ideas have withered. Good writing, sharing of code and ideas still remains a value proposition for personal websites.