[SciPy-user] Confusing BLAS/LAPACK situation on Mac OS X

Robert Kern robert.kern at gmail.com
Sat Jan 28 15:43:48 CST 2006

Brian Granger wrote:

> What about:
> /System/Library/Frameworks/Accelerate.framework/Frameworks/vecLib.framework/
> Versions/Current/libLAPACK.dylib
> and
> Headers/clapack.h
> Also, Apple's docs on Accelerate claim that they include clapack.
> Are these incomplete/unusable for some reason?  It seems silly to build ATLAS if it is already there.

Look at the symbols in libBLAS.dylib and libLAPACK.dylib. You can see the CBLAS
versions in libBLAS.dylib, but there are only the FORTRAN versions in
libLAPACK.dylib. You are right that the docs claim (correctly) that
Accelerate.framework contains CLAPACK. However, I goofed and referred to things
incorrectly. CLAPACK is simply an implementation of FORTRAN LAPACK in C. It uses
FORTRAN column-major arrays. The flapack module links against these. However,
ATLAS also provides row-major versions of some(?) LAPACK functions to match the
row-major CBLAS routines. The clapack module wraps these. These are not included
in Accelerate.framework, although the row-major CBLAS versions are.

Robert Kern
robert.kern at gmail.com

"In the fields of hell where the grass grows high
 Are the graves of dreams allowed to die."
  -- Richard Harter

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