plotfunc represents a complex expression E
(such that re(E) is not identically 0 on the discretization mesh)
by the surface z=abs(E) where arg(E) defines the color
from the rainbow. This gives an easy way to
see the points having the same argument.
Note that if re(E)==0 on the discretization mesh,
it is the surface z=E/i that is represented with rainbow colors
(cf 6.2.3).

The first argument of plotfunc is E,
the remaining arguments are the same
as for a real 3-d graph (cf 6.2.2).

Input :

plotfunc((x+i*y)

`^`

2,[x,y])Output :

A graph 3D of z=abs((x+i*y)

`^`

2 with the same color for
points having the same argumentInput :

plotfunc((x+i*y)

`^`

2x,[x,y], display=filled)Output :

The same surface but filled

We may specify the range of variation of x and y and the number of
discretization points.

Input :

plotfunc((x+i*y)

`^`

2,[x=-1..1,y=-2..2], nstep=900,display=filled)Output :

The specified part of the surface with x between -1 and 1, y between -2 and 2 and with 900 points