TRIQUIVER(TRI,X,Y,U,V) plots velocity vectors as arrows with components in U and V at the triangle vertices identified by the triangulated data given by TRI, X, and Y. U and V must have as many elements as X and Y.
Thank you very much for your submission. In your example the magnitude of the gradient and trigradient seem to differ. Presumably, it is due to vector scaling. Could you elaborate on this? Accurate scaling is essential of course.