Re: Multiplot fails in postscript mode

[Ethan A M. <merritt@u.washington.edu>]

On Friday 04 June 2004 04:56 pm, you wrote:

I'm not sure I can make things any clearer, but I'll try.

> The way I use gnuplot, I would have expected the following.
> "set multiplot": tells the plot command that the canvas shouldn't be
> cleared before the plot.

Not quite correct. "set multiplot" tells gnuplot that the canvas should not
be reset *after* the plot, or indeed after the next several plots leading
up to "unset multiplot".  It also tells gnuplot there are a number of other
things it should not allow while in multiplot mode (most of them pretty
obvious - like not change the terminal type).

> If I wanted to change the canvas size (for example, the resolution of a
> bitmap plot, or the paper size), I would expect this to be done using "set
> terminal <whatever> <canvas size>".

I was using "canvas" to refer to the subarea within the physical page
or window or piece of paper within which the plot lies.  The size of the
page or window or paper is a separate specification, and is unfortunately 
terminal-specific. For instance
	set term png size 600,480
	set term dumb 79 49
Perhaps even more unfortunately, there is no such option for the
PostScript terminal.  That may be the real bug here, if there is one. 

Anyhow, "set size" is independent of this, and controls how much of that
terminal size (or page size) can be written on by the next plot.

Consider:

	set term png size 600,480
	set size 0.5, 0.5
	plot sin(x)

	set term png size 300,240
	set size 1,1
	plot sin(x)

Both of these will produce a graph that occupies roughly 300x240
pixels, but the first one will be surrounded by a lot of empty space
in a large window.  The second one will be in a smaller window which
it mostly fills.

In the second plot of your example you told the postscript driver
that it could only write to half of the total paper ("set size 1,0.5"),
and so that's what it did.

-- 
Ethan A Merritt
Department of Biochemistry & Biomolecular Structure Center
University of Washington, Seattle