Re: pngcairo: suggestion for additional option

[Allin C. <cot...@wf...>]

On Wed, 21 Nov 2007, Ethan Merritt wrote:

(about extracting bounds information from gnuplot, e.g. for a PNG 
file)

> I believe the suggestion was that one could achieve this by the
> following lines:
> 
>   set print "plot_coords.dat"
>   print "x limits: ", GPVAL_X_MIN, GPVAL_X_MAX
>   print "x2 limits: ", GPVAL_X2_MIN, GPVAL_X2_MAX
>   print "y limits: ", GPVAL_Y_MIN, GPVAL_Y_MAX
>   print "y2 limits: ", GPVAL_Y2_MIN, GPVAL_Y2_MAX
>   print "graph limits: ", GPVAL_GRAPH_XMIN, GPVAL_GRAPH_XMAX
>   ... and so on

I'm attaching a small patch to eval.c that implements 
GPVAL_GRAPH_XMIN, GPVAL_GRAPH_XMAX, GPVAL_GRAPH_YMIN and 
GPVAL_GRAPH_YMAX. In the context of bitmapped output, these values 
should represent the pixel coordinates of the actual graph area.

Those more familiar than I with the gnuplot architecture will no 
doubt be able to see if there's a better way of doing this.

-- 
Allin Cottrell
Department of Economics
Wake Forest University, NC