2014-03-28 22:55 GMT+01:00 Julian Taylor <jtaylor.deb...@googlemail.com>: > On 28.03.2014 22:38, Olivier Grisel wrote: >> 2014-03-28 22:18 GMT+01:00 Nathaniel Smith <n...@pobox.com>: >>> I thought OpenBLAS is usually used with reference lapack? >> >> I am no longer sure myself. Debian & thus Ubuntu seem to be only >> packaging the BLAS part of OpenBLAS for the libblas.so symlink and >> uses the reference implementation of lapack for the liblapack.so >> symlink. > > You can link the reference lapack with any library providing a BLAS > compatible API/ABI. ATLAS and OpenBlas are ABI compatible with reference > BLAS which allows replacing the library via LD_PRELOAD or debian > alternatives without recompiling. > > Both ATLAS and OpenBlas provide a subset of optimized lapack functions, > but they are optional. On Debian/Ubuntu you can install ATLAS lapack but > then you are also forced to use ATLAS blas. > > I am not familiar with how relevant the optimized parts of lapack for > the general use case. > >> >> I observed a sparse leastsqr bug when linking scipy against the full >> OpenBLAS under OSX that I could not reproduce under with the openblas >> + lapack combo shipped Ubuntu so there might be a difference. But that >> could also be caused by a version / platform discrepancy between my >> two setups. >> > > what kind of a bug? wrong result or crash?
Here it is: https://github.com/scikit-learn/scikit-learn/issues/2986 I have not found the time to investigate yet. > Which target did openblas use > when compiling on macos? or was it a dynamic build? (see the name of the > built static library) I think I used target=NEHALEM that time (but not 100% sure). -- Olivier http://twitter.com/ogrisel - http://github.com/ogrisel _______________________________________________ NumPy-Discussion mailing list NumPy-Discussion@scipy.org http://mail.scipy.org/mailman/listinfo/numpy-discussion