From: Patrick Doyle <wpdster@...>
Date: 2008-08-18T10:46:45+09:00
Subject: Re: vector graphics library with pan and zoom

Hi Joel,
Thanks for the tip.  However, I'm not planning on interfacing Tkar to
MATLAB, I just mentioned MATLAB because I am quite enamoured of the
visualization capabilities provided by the "plot" command in MATLAB,
and was hoping to find something of a similar nature I could access
from a Ruby script.  Thus far, I have found (or, more accurately, been
shown -- by you) Tkar, which provides the pan and zoom capability I
desire.  I have also found rgplot, which provides an interface to
gnuplot.

For the ridiculously large amount of data I want to plot, I have found
TKar to be too slow for my needs (taking 20 minutes to plot a single
data set).  gnuplot can handle that amount of data easily, but the
pipe between ruby and gnuplot seems to overflow as the data are
written.  (I found a description very similar to the problem I have
observed on an Octave mailing list.  Unfortunately, I have misplaced
that page at the moment).

So, right now I am looking at 4 options:
1) Read through your Tkar code enough to extract out the code that
plots lines and arcs on a zoomable, pan-able canvas and integrate that
with my code.

2) Find that darn web page again, verify that Ruby has the same issue
as Octave and, hopefully, can be fixed by the same patch proposed, and
submit a patch against Ruby to fix that.

3) Give up on plotting altogether.

4) Dump my data to a file readable and plottable by MATLAB and use
MATLAB to visualize my data.

--wpd