[pstricks] psgraph/pspicture variables psymax or numpsyunits

[Buddy Ledger]

Hello All:

Does anyone know of an accessible parameter for the pspicture or psgraph 
environments which would report the dimensions of the environment.

The application:

I want to draw items (in postscript) which are scaled to the 
environment.  Say I want a legend at 0.75*total height and 0.75*total 
width.  If I change the plot limits I don't want to manually adjust the 
position idealy the position would be calculated automatically via

0.75 \psxmax mul  0.75 \psymax mul moveto

I've assumed here that the imaginary psymax and psxunit are in the plot 
units not pts (if pts divide by psxunit and psyunit as appropriate). 

If these don't exist I may just redefine psgraph so that they are 
recording if the \def (I didn't see any indication that parameters of 
this type were provided) would there be any naming conflicts by adding 
the two parameters psxmax and psymax?

Thanks,

Buddy