>I have two questions I was hoping someone could help me with. I've looked in
>the faq and the manual and didn't find these addressed.
>First, is there a way to change the default page/plot dimenstions in
>gnuplot? I'd like to generate a plot for legal or 11x17 paper, or better
>yet, a plot to print on a large format plotter (several feet in width and
For such a large plot you probably want PostScript output.
The gnuplot command 'set term post' does not have a separate sub-option
for specifying the page size, so you have to use the generic command
'set size <xmult>,<ymult>'
Since the default PostScript page size is 8.5x11, to get 11x17 instead
you would want 'set size 11/8.5, 17/11'
Quote:>Second, I've been amazed at gnuplots ability to plot large data sets.
>Unfortunately, I managed to kill it on a 3 month data file with 1 second
>samples. I assume this is largely due to an insufficient amount of ram on
>my machine and not some other limit in gnuplot. My question is simply,
>will a memory addition do the trick, or are there some hard limits to the
>number of data points gnuplot can plot?
It is unlikely to be limited by the amount of ram, although conceivably
it is limited by the amount of virtual memory (= ram + swap space on disk).
Gnuplot will keep on requesting more virtual memory as more data points
are read in, up to the point where the operating system refuses to give
it any more.
You will have to provide more information about what operating system
you are running under. On a unix-like system it is possible that you
can increase the amount of memory available to your process by using
a shell command such as 'unlimit'.
Quote:>Or is there perhaps a better way to make a plot of this magnitude?
Maybe. It depends on what type of plot you are making. For instance,
it turns out that PostScript is a bad choice for huge scatter-plots,
since it writes out a separate command to draw each point even if
the points large fall on top of each other. This can produce immense
output files, which may not be printable because they exhaust the
resources available to your printer or printer driver.
In such a case one of the raster-mode plots is more practical, since
the size of the output file is independent of the number of points
that are plotted. This won't, however, change the fact the gnuplot itself
will need lots of memory to handle the points as they are read in.