contourc example

[John W. Eaton]

On 27-Apr-2007, Geordie McBain wrote:

| The example `c = contourc (x, y, z, linspace (0, 2*pi, 10));' in the
| help string for contourc can't be run as it stands since x, y, and z
| aren't defined.  This limits its usefulness somewhat.
| 
| I suggest a self-contained example, like
| 
| %<---
| octave-2.9.10:1> contourc (x = 0:2, y = x, z = x' * y, 2:3) 
| ans =
| 
|    2.0000   2.0000   1.0000   3.0000   1.5000   2.0000
|    2.0000   1.0000   2.0000   2.0000   2.0000   1.5000
| %<---
| 
| as in the attached patch.  The example also shows the (reasonably
| concise) output.

I applied the patch and also moved the x, y, and z assignments outside
of the argument list.

Thanks,

jwe