Contourf Z must be at least a 2x2 matrix error

Hi all,while creating contourf plot I have Z must be at least a 2x2 matrix.I couldn't fix it. If you've any idea to fix it I'd be appreciate.Thanks in advance.

[KSSV]

Unrecognized function or variable 'SPODpost'.

Error in Rainbow_POD (line 26)
mode = SPODpost(a(:,1:idx));
 

Answer 1

[Walter Roberson]

mode = SPODpost(a(:,1:idx));

That function was not included

    contourf(X,Y,Vi(:,:,mode(idx).ind(2)),10,'edgecolor','none')

For that to be valid, Vi(:,:,mode(idx).ind(2)) must be a 2D array. But...

>> whos -file POD.mat

Name Size Bytes Class Attributes

U 1x101 808 double

V 1x101 808 double

X 1x101 808 double

Y 1x101 808 double

and

% Ui,Vi,Wi,... :POD modes (spatial modes). Number of output modes depends
%               on the number input velocity components. The dimension of
%               the output data is the same as the input data, whereas the
%               last dimension contains individual modes instead of
%               snapshots.

The input V is a vector, and with the output Vi being the same size as the inputs, that means that Vi must be a vector.

Your plotting code with contourf() assumes that Vi is 3 dimensional, but it is only a vector.

You will not be able to do contouring in this situation.