Hi,
I am using 5.11.0 with gnuplot 4.24c4. I encountered the following problem:
(%i5) f(x,y) := 10*sin(sqrt(x^2+y^2))/sqrt(x^2+y^2)$
(%i6) plot3d(f(x,y), [x,-20,20],[y,-20,20], [grid,80,80]);
Maxima encountered a Lisp error:
Error during processing of --eval option "(cl-user::run)":
The value T is not of type DOUBLE-FLOAT.
Automatically continuing.
To reenable the Lisp debugger set *debugger-hook* to nil.
(%i7)
This doesn't happen if I use [grid,50,50].
Kostas