MATLAB: Does gradient function calculates wrong dimensions

Question

Hi there,

Why does the gradient function calculates the first two dimensions wrong?

Example:

[mshx,mshy,mshz] = ndgrid(0:.1:10,0:.1:10,0:.1:10);
[gxx,gyx,gzx] = gradient(mshx);
[gxy,gyy,gzy] = gradient(mshy);
[gxz,gyz,gzz] = gradient(mshz);

Here all gij are zero except for gyx, gxy, gzz. But how can I calculate the gradient more consistently so that all gij are zero except for gxx, gyy, gzz?

Thank you for your help.

Best regards

Michael

Answer 1

Use meshgrid instead of ndgrid

[mshx,mshy,mshz] = meshgrid(0:.1:10,0:.1:10,0:.1:10);
[gxx,gyx,gzx] = gradient(mshx);
[gxy,gyy,gzy] = gradient(mshy);
[gxz,gyz,gzz] = gradient(mshz);