From: Changgong Zhang <longbowzhangchina@gm...>  20140702 19:22:32

Hello Teem users, I have a question about the usage of *tenInterpDistanceTwo_d* function. I want to calculate the orientation distance between two tensors. Tensor A = [4, 0, 0, 4, 0, 4] i.e., perfect sphere. Tensor B = [10, 0, 0, 1, 0, 1] i.e., linear shape tensor. My expectation is that if a tensor is compared with a sphere tensor, the orientation should be 0. *tenInterpDistanceTwo_d* can give me a value very close to 0. But if I change B to [1, 0, 0, 10, 0, 1] or [1, 0, 0, 1, 0, 10], the function returns a very large orientation distance value. But B is still a linear shaped tensor. This is not what I expect. What is the reason behind this? Furthermore, in the paper *GeodesicLoxodromes for Diﬀusion Tensor Interpolation and Diﬀerence Measurement*, page 6, it says '*'there is little orientation change between isotropic and anisotropic* *tensors of comparable size*". In this case, B is very anisotropic tensor and A is a perfect isotropic tensor and both have exactly the same trace (=12, i.e., the size in the context), why it returns a large value far from 0. Thank you very much. Changgong Zhang Ph.D candidate in Computer Graphics and Visualization section TU Delft 