[Numpy-discussion] Segfault with QR Decomposition

2013-10-09 Thread Charanpal Dhanjal
Oops, the second line should have been export OPENBLAS_NUM_THREADS=8 ___ NumPy-Discussion mailing list NumPy-Discussion@scipy.org http://mail.scipy.org/mailman/listinfo/numpy-discussion

[Numpy-discussion] Segfault with QR Decomposition

2013-10-09 Thread Charanpal Dhanjal
> >/ I get a segmentation fault upon running the following: > />/ > />/ import numpy > />/ A = numpy.ones((700, 8)) > />/ Q, R = numpy.linalg.qr(A) > />/ > />/ on Python 2.7.3, Linux 64-bit using numpy 1.9.0.dev-ec3603f linked > />/ against OpenBLAS. If A is a smaller matrix then the QR decompo

[Numpy-discussion] Segfault with QR Decomposition

2013-10-09 Thread Charanpal Dhanjal
I get a segmentation fault upon running the following: import numpy A = numpy.ones((700, 8)) Q, R = numpy.linalg.qr(A) on Python 2.7.3, Linux 64-bit using numpy 1.9.0.dev-ec3603f linked against OpenBLAS. If A is a smaller matrix then the QR decomposition works (for example A has shape (40

Re: [Numpy-discussion] Eigenvalues did not converge

2011-09-01 Thread Charanpal Dhanjal
ATLAS and see >> if that helps (or, more generally, determining which blas/lapack you >> are linking against, and try something else). >> >> Paul >> >> On 29. aug. 2011, at 16.21, Charanpal Dhanjal wrote: >> >> > I posted a similar question abou

Re: [Numpy-discussion] Eigenvalues did not converge

2011-08-29 Thread Charanpal Dhanjal
I posted a similar question about the non-convergence of numpy.linalg.svd a few weeks ago. I'm not sure I can help but I wonder if you compiled numpy with ATLAS/MKL support (try numpy.show_config()) and whether it made a difference? Also what is the condition number and Frobenius norm of the ma

Re: [Numpy-discussion] SVD does not converge on "clean" matrix

2011-08-14 Thread Charanpal Dhanjal
Thanks very much Lou for the information. I tried delving into the C code and found a line in the dlasd4_ routine which reads: for (niter = iter; niter <= MAXITERLOOPS; ++niter) { This is apparently the main loop for this subroutine and the value of MAXITERLOOPS = 100. All I did was increase th

Re: [Numpy-discussion] SVD does not converge on "clean" matrix

2011-08-14 Thread Charanpal Dhanjal
I had a quick look at the code (https://github.com/numpy/numpy/blob/master/numpy/linalg/linalg.py) and the numpy.linalg.svd function calls lapack_lite.dgesdd (for real matrices) so I guess the non-convergence occurs in this function. As I understood lapack_lite is used by default unless numpy i

Re: [Numpy-discussion] SVD does not converge on "clean" matrix

2011-08-12 Thread Charanpal Dhanjal
Thank Nadav for testing out the matrix. I wonder if you had a chance to check if the resulting decomposition contained NaN or Inf values? As far I understood, numpy.linalg.svd uses routines in LAPACK and ATLAS (if available) to compute the corresponding SVD. I did some complementary tests on De