thouis
commented
12 years ago Comment in Trac by atmention:charris, 2008-10-15
It isn't in numpy, it is in scipy.linalg.
In [1]: import scipy.linalg as la
In [2]: help(la.lu_factor)
In [3]: print la.lu_factor.__doc__
Compute pivoted LU decomposition of a matrix.
The decomposition is::
A = P L U
where P is a permutation matrix, L lower triangular with unit
diagonal elements, and U upper triangular.
Parameters
----------
a : array, shape (M, M)
Matrix to decompose
overwrite_a : boolean
Whether to overwrite data in A (may increase performance)
Returns
-------
lu : array, shape (N, N)
Matrix containing U in its upper triangle, and L in its lower triangle.
The unit diagonal elements of L are not stored.
piv : array, shape (N,)
Pivot indices representing the permutation matrix P:
row i of matrix was interchanged with row piv[i].
See also
--------
lu_solve : solve an equation system using the LU factorization of a matrix
Notes
-----
This is a wrapper to the *GETRF routines from LAPACK.Please don't use the tickets to ask questions, post to the numpy/scipy mailing lists.
Original ticket http://projects.scipy.org/numpy/ticket/933 Reported 2008-10-15 by trac user moo, assigned to unknown.
http://www.scipy.org/NumPy_for_Matlab_Users Suggests that your package includes LU decomposition. It's a good page, aside from being hilariously out of date, as http://scipy.org/doc/numpy_api_docs/numpy.linalg.html seems to suggest it doesn't even exist anymore, which is a lovely bunch of coconuts. Has it migrated to somewhere super obvious and I'm just an idiot for relying on Google and common sense, or has that functionality been removed as a "feature"?