It seems that the error I had trying to get a postscript output
out of plot3d was due to a misinitialised array in
src/plot.lisp (all elements were initialised to nil rather than to 0).
The following patch seems to correct the problem, at least under clisp.
lg
--- /home/lucag/cvs/maxima/src/plot.lisp 2003-08-04 12:56:22.000000000 +0200
+++ /mnt/tmp/maxima/src/plot.lisp 2003-08-06 12:11:40.000000000 +0200
@@ -392,7 +392,7 @@
(lisp::atan z2 z1 ))))
(defun $ps_axes ( rot )
- (let ((tem (make-array 9 :element-type 'double-float)))
+ (let ((tem (make-array 9 :element-type 'double-float :initial-element 0)))
(setf (aref tem 0) 4.0)
(setf (aref tem 4) 4.0)
(setf (aref tem 8) 4.0)