principal_axes_from_inertia_tensors¶
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halotools.mock_observables.
principal_axes_from_inertia_tensors
(inertia_tensors)[source] [edit on github]¶ Calculate the principal eigenvector of each of the input inertia tensors.
Parameters: inertia_tensors : ndarray
Numpy array of shape (npts, 3, 3) storing a collection of 3x3 symmetric positive-definite matrices
Returns: principal_axes : ndarray
Numpy array of shape (npts, 3) storing a collection of 3d principal eigenvectors
eigenvalues : ndarray
Numpy array of shape (npts, ) storing the eigenvalue of each principal eigenvector
Notes
The function
inertia_tensor_per_object
calculates the inertia tensors \(\mathcal{I}_{\rm i}\) for a collection of points inside a 3d mass distribution.