Re: Again: canvas size

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

On Wednesday 12 October 2005 02:39 pm, Harald Harders wrote:
> 
> Until now, the screen coordinates are the only measure (except character,
> see above) that can remain constant independent on the graph, canvas or
> whatever size. If the screen coordinate system is changed to be hardcoded
> to range 0:1 the only absolute coordinate system gets lost.

Then let let us fix that problem directly, instead of mis-using the
screen size simply to allow specification of arrows in absolute coordinates.

Introduce a new coordinate system "absolute", or maybe even the specific
units  "in", "cm", "pt", "pixel".

That would work far better than misusing the screen coords, because the
screen coords are not guaranteed to have an aspect ratio of 1.  Indeed
usually they do not, which I have noticed is a problem for generating
arrowheads that look the same independent of the direction the arrow is
pointing.


> Where is the advantage of generating two plots with the same size by
> giving different measures:
> 
> set terminal png size 640,480
> set multiplot
> set size 1,1
> ...
> 
> and
> 
> set terminal png size 640,600
> set multiplot
> set size 1,480./600
> 
> I do not understand this.

If those two command sequences produce the same result, it is a bug.
But they don't.

The first one produces a 640x480 image that is entirely filled
by the plot.

The second one produces a 640x600 image that contains a plot
in the lower 480 pixels, but is blank above that.  Presumably that
blank area will be occupied by the next plot in the multiplot
sequence.  Is that not the entire purpose of multiplot?


-- 
Ethan A Merritt       merritt@u.washington.edu
Biomolecular Structure Center
Mailstop 357742
University of Washington, Seattle, WA 98195