cplxmap issue when trying to plot z^(1/3)

I am trying to plot z^(1/3) using cplxmap. However, whenever I run my code, I recieve the following errors that are occuring in the function cplxmap:

Error using mesh (line 79)
Z must be a matrix, not a scalar or vector

Error in cplxmap (line 31)
mesh(x,y,m*s,blue*s);

Error in paper (line 16)
cplxmap(z, w)

The code I am running is:

clear all
close all

r = linspace(0, 1, 1000);                    % radius vector
theta = linspace(0, 2*pi, 1000);             % angle vector

z = r.*exp(1i*theta);                        % defines cplxgrid
x = real(z);                                 % real z
y = imag(z);                                 % imaginary z
w = z.^(1/3);                                % w = z^(1/3)
u = real(w);                                 % real w 
v = imag(w);                                 % imaginary w

figure(1);
cplxmap(z, w)
colormap(jet)

[chadi cream]

z must me a matrix not a vector. in your case it is a vector, same as r and theta.

[chadi cream]

you can

z=cplxgrid(10); w=z.^(1/3); cplxmap(z, w)

[Caba]

You have to create a meshgrid (matrix) from the two column vectors, r and theta. Reduce the number of elements from 1000 to something more manageable, e.g. 51. Try different values in R=linspace(0,1,M), like M=21,51,101

R = linspace(0, 1, 51); % radius vector Theta = linspace(0, 2*pi, 51); % angle vector [r,theta] = meshgrid(R,Theta); % creating a meshgrid

Answer 1

[Star Strider]

A bit further down in the documentation for that example, it mentions cplxroot. See if:

cplxroot(3)

does what you want. If you want to generate your own plot, in that example ‘z’ is generated by the cplxgrid function.