Re: Plot3D error
- To: mathgroup at smc.vnet.net
- Subject: [mg7331] Re: [mg7322] Plot3D error
- From: Andrei Constantinescu <constant at athena.polytechnique.fr>
- Date: Tue, 27 May 1997 22:26:58 -0400 (EDT)
- Sender: owner-wri-mathgroup at wolfram.com
On Fri, 23 May 1997, Darrmis wrote:
> Hello everybody.
>
> Can anyone tell me what's wrong?
>
> Clear[x,y,z];
> Plot3D[(1+2 x+y^2)^(1/3),{x,-10,10},{y,-10,10}]
>
> gives me error: Plot3D::gval: Function value 0.4+0.7I at grid point ...is
> not real
> etc.
> And function is not completely plotted.
> Any suggestion would be appreciated.
>
> Karl Kevala
>
>
There is really a problem to plot as your function ^(1/3) has actually 3
solutions, one real and two complex. You have to choose the real one
in order to plot it !
Cheers,
Andrei