title: Plotting Ellipsoid in Python
body: <p>I have a 3x3 positive definite matrix (a diffusion tensor to be specific) and am hoping to plot an ellipsoid who's axis directions correspond to the eigenvalues of the tensor with scale proportional to the associated eigenvalues. I am working in Python/jupyter notebooks. I have successfully used the code in the answer to <a href="https://stackoverflow.com/questions/27302055/ellipsoid-creation-in-python">this question</a> to plot an ellipsoid with scaled axes, but I can not figure out how to alter the axis orientations to be along the directions of the eigenvectors.</p>