----- file created by makedoc on: Tue Apr  1 15:29:55 2008
----- Documentation for /scisoft/xop2.3/extensions/shadowvui/src/lib/slopes.pro -----

 returns the x and y slope errors of a surface

 FUNCTION slopes,z,x,y 
 or
 FUNCTION slopes,a    where a is the structure with the surface (a.x, a.y, a.z)

 MSR 1994

