Re: Again: canvas size

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

On Monday 10 October 2005 02:37 pm, Harald Harders wrote:
> At the moment, there are two different possibilities to change
> the canvas size (partly depending on the terminal):
> 
> - Use 'set size xcan,ycan' before using 'set terminal'.
>   This leads to screen coordinates 0,0 in the lower left corner and
>   xcan,ycan in the upper right corner.

That does seem to be true currently.
I really dislike this as being totally counter-intuitive.   
See for example, today's bug report #1324011


> - Use 'set terminal <term> size xterm,yterm'.
>   This leads to screen coordinates 0,0 in the lower left corner and
>   1,1 in the upper right corner.

This is not true currently.
What it does is to define range screen 0 -> screen 1 as spanning
xterm pixels.  That may or may not be the same as the upper right
corner of the screen, as you pointed out yourself just above.
 
> Say, you want to have many plots in one document with identical size. If
> one of these plots is a multiplot, it is useful to have a canvas with
> maximal screen coordinates 1,2.

I am totally lost here.  Can you post a web page that contains an 
example of such a document?  Won't you get exactly what you describe
without specifying "set size" at all?  Each plot, multi- or single-
will be of identical size.

 
> I propose following structure:
> 
> - The canvas size is defined exclusively by the 'set terminal' commands,
>   e.g., 'set terminal png size 640,480' or 'set term post size 6in,4in'.

I agree with this part.

> And for a multiplot, you can use
> 
> set screen-coordinate max 1,2
> set terminal postscript size 5in,6in
> 
> This would lead to identical absolute screen coordinate lengths in both
> cases.

I do not understand this at all. 
What is "screen coordinate length"?
Consider the two following command sequences:

A)
set term png size 200,200
set output 'A.png'
set screen-coord max 1,1
set multiplot layout 2,1
plot <foo>
plot <baz>

B)
set term png size 200,200
set output 'B.png'
set screen-coord max 1,2
set multiplot layout 2,1
plot <foo>
plot <baz>

Both png images are 200x200 pixels, right?
Will B.png contain both plots, or will it only contain one of them?
If it contains both, in what way does it differ from A.png?
 
> What do you think of this structure?

So far I don't understand it :-)


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