Hello,
I am trying to add support for sparse matrices in RandomizedLasso. I'm
stuck at this line.
swap, nrm2 = linalg.get_blas_funcs(('swap', 'nrm2'), (X,))
When X is sparse. this fails with the following error.
AttributeError, flags not found.
Is this expected behaviour?
Any help would be
Hi Manoj,
For efficiency, the BLAS api defines different functions for different
underlying datatypes (float32, float64, complex64, complex128). The
scipy get_blas_funcs utility has the role of getting the Python
wrapper for the given BLAS functions (in this case 'swap' and 'nrm2',
that's
2014-03-18 19:56 GMT+01:00 Manoj Kumar manojkumarsivaraj...@gmail.com:
Hello,
I am trying to add support for sparse matrices in RandomizedLasso. I'm stuck
at this line.
swap, nrm2 = linalg.get_blas_funcs(('swap', 'nrm2'), (X,))
When X is sparse. this fails with the following error.
2014-03-18 20:09 GMT+01:00 Olivier Grisel olivier.gri...@ensta.org:
BLAS functions only work for contiguous (dense) arrays. You will need
scipy sparse equivalent functions to work with CSR or CSC
datastructures. For instance the `nrm2` function could be emulated by:
row_norms =
Hi Vlad and Oliver,
Thanks a lot.
On Wed, Mar 19, 2014 at 12:41 AM, Olivier Grisel
olivier.gri...@ensta.orgwrote:
2014-03-18 20:09 GMT+01:00 Olivier Grisel olivier.gri...@ensta.org:
BLAS functions only work for contiguous (dense) arrays. You will need
scipy sparse equivalent functions
2014-03-18 20:09 GMT+01:00 Olivier Grisel olivier.gri...@ensta.org:
I don't know how to efficiently swap 2 rows of a CSR matrix. Maybe the
algorithm would have to be adapted a bit in the sparse case.
Not familiar with the code but if swaps are common, you could keep an
array of pointers or
