Re: Again: canvas size

[Harald H. <h.h...@tu...>]

On Tue, 11 Oct 2005, Ethan Merritt wrote:

> 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.

I ment the default case without prior 'set size'.

> > 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.

You could compare the screen coordinate ranges with the ranges in a plot.
Would you understand if I say:

set xscreenrange [0:1]
set yscreenrange [0:2]

This would mean, the lower left corner of the canvas has the screen
coordinates 0,0 and the upper right has 1,2.

Have a look at http://www.harald-harders.de/gnuplot/canvas/

> > 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"?

I do not know the correct English term. If you draw an arrow from screen
0,0 to screen 1,1 in a plot with

set screen-coordinate max 1,1
set terminal postscript size 4in,3in

and the same arrow (0,0 to 1,1) in a plot with

set screen-coordinate max 1,2
set terminal postscript size 4in,6in

this would lead to two identical arrows while in

set screen-coordinate max 1,1
set terminal postscript size 4in,6in

the arrow would point to a position at double height of the first two
cases.


> 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?

I am not talking about the automatically scaled plots but of plots that
have a defined size given by the user. See the www page for that.
Of course, automatically placed and scaled plots shall not be influenced
by the 'set screen-coord' command.

Best regards
Harald

-- 
Harald Harders
h.h...@tu...
http://www.harald-harders.de