Data Visualization using Perl/Tk

Idean writes "Generating a visual representation is often the best way to understand large data sets, but standard tools such as gnuplot often fall short. This article shows how to use Perl/Tk, the standard GUI toolkit for Perl, to quickly build custom plotting and graphing tools."

Comments

Re:Perl or Line Noise

[Phillup]

And how did your control group do?

What language was Perl compared to using this methodology?

Did the test subjects have experience with Perl? And, what of the control group?

Perl is different, no doubt about it. But, it doesn't *have* to look like line noise.

See also: PDL

[bill_mcgonigle]

I'll just copy what their homepage says:

PDL ("Perl Data Language") gives standard Perl the ability to compactly store and speedily manipulate the large N-dimensional data arrays which are the bread and butter of scientific computing.

PDL turns perl in to a free, array-oriented, numerical language similar to such commerical packages as IDL and MatLab. One can write simple perl expressions to manipulate entire numerical arrays all at once. For example, using PDL the perl variable $a can hold a 1024x1024 floating point image, it only takes 4MB of memory to store it and expressions like $a=sqrt($a)+2 manipulate the whole image in a few seconds.

It offers both 2D and 3D visualization.

Re:Use plotting software instead

[spencerogden]

"and I don't see how Perl could help, as numerical processing is certainly not its strength!"

Have you explored PDL (piddle)? I find it to be a very powerful way to manipulated datasets.

Re:Use plotting software instead

[acaird]

Another entry in the "good free software for plotting that is like Matlab" catagory (yes, very specific), is Octave.

From their web site: "GNU Octave is a high-level language, primarily intended for numerical computations. It provides a convenient command line interface for solving linear and nonlinear problems numerically, and for performing other numerical experiments using a language that is mostly compatible with Matlab. It may also be used as a batch-oriented language."

Statistical Data

[neglige]

Examples of complicated graphs include specialized bar-and-whiskers plots

I had to cope with box-and-whisker plots to visualize data gathered from a statistical survey. Frankly, Perl/Tk was nothing I looked into (and I love Perl & Tk!). I entered the data into an OpenOffice spreadsheet (which made the statistical calculation very easy!) and googled for a solution. There are many commercial packages available for Excel, but this article was really helpful. I managed to create a similar solution for OO (I'm not sure if the result is of interest to anyone - if so, msg me or something).

Does anyone know a repository for statistical analysis programs? Because if you only need to run an analysis once, you think twice about hacking a Perl/Tk program (the 'clean' approach) unless you are a true Perl wiz - the time needed to write the program is (with my programming abilites) two or three times longer than looking for another one shot solution (the 'practical' approach).

If there was a central repository for this, you a) knew where to look first and b) had an incentive to write the program to save someone else the time. Yes, I know I could put it up to some website, but I really doubt anyone would find it or even look for it...

much better choices around

[penguin7of9]

If you want statistically sound data analysis and graphing, look no further than the R Project. It's a complete programming environment and is extensively used by working statisticians.

Python, Numerical Python, various Python plot packages, and VTK also make for very powerful visualizations if you want something more do-it-yourself.