Re: [Numpy-discussion] Zero row in SVD's unitary matrix on some Mac's

2011-04-26 Thread Rob Beezer
On 04/26/2011 11:25 AM, Pauli Virtanen wrote: > I think it is worth testing if this change fixes it. Note that current > LAPACK docs have the number 7 there instead of 5, so there may really be > a bug here. It appears to me the problem is more subtle than just a strict comparison between the num

Re: [Numpy-discussion] Zero row in SVD's unitary matrix on some Mac's

2011-04-26 Thread Rob Beezer
On 04/26/2011 10:19 AM, Ralf Gommers wrote: > If it is an Accelerate bug it got fixed on OS X 10.6. Below is the > output with both current master and 1.5.1. It may be worth checking > this on 10.5 with the binary Numpy installer from Sourceforge to make > sure it's not the Sage build process causi

Re: [Numpy-discussion] Zero row in SVD's unitary matrix on some Mac's

2011-04-25 Thread Rob Beezer
Thanks for the reply, Pauli. I suspected this might be the case, but was hoping maybe this was something that had been seen before. I've included your suggestions on the bug report for Sage. Rob On 04/25/2011 10:57 AM, Pauli Virtanen wrote: > The Numpy routine is a very thin wrapper of LAPAC

[Numpy-discussion] Zero row in SVD's unitary matrix on some Mac's

2011-04-25 Thread Rob Beezer
I am working to make many of NumPy's matrix decomposition routines available in Sage. As part of testing a new routine, we have found some odd behavior with the singular value decomposition. On certain Mac's, the numpy built in Sage will return the second of the unitary matrices with a row of