Re: Plotting performance with cywin running under Win7

[Francesco Potortì]

Matthew Reich:
>> Running Octave through cygwin under Win 7 or under XP, graphics
>> performance for plotting suffers from slow GUI response speed. Following
>> the suggestions in Octave documentation, I am using fltk rather than
>> gnuplot, but the plotting speed and GUI response speed does not differ
>> much between the two.  In particular, using fltk, the initial rendering
>> is slow, especially for vectors over

Marco Atzeri:
>> several hundred thousand elements.
>
>the problem is the size, you need to trim down the number of points.

If you speak about simple 2-d plots, with x and y, you can use the
plotdecimate function, in the plot package.  It removes the "useless"
points  before plotting, that is, those points which would not change
the visual appearance of the plot.

It is intended to (greatly, in many cases) reduce the size of a plot
saved in a vector format (like PS or PDF).  It will certainly also
reduce the time needed to interactively generating a plot, but at the
expense of time needed to decimate, so I don't know if it brings any
advantages time-wise.

>> For plots of all data sizes, the window becomes gray when moved, after
>> plotting another window, or intermittently after fltk GUI operations.
>> Convincing the window to redraw can take some time.  GUI response for
>> zooming is slow and sporadic.

As far as these problems are concerned, you will certainly see an
improvement using plotdecimate before plotting.

>> Also, any suggestions for which formats best export graphics for pasting
>> into MSWord documents?

Generally speaking, vector formats are the best for plotting.  I use
EPS.  In my experience, EPS is okay for MS word.

As a second choice, use a raster format with non-lossy compression.  PNG
is the obvious choice in this respect.  Avoid lossy compression formats,
like JPEG.

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