Hi Guillem
On Wed, May 02, 2007 at 12:38:12AM +0200, Guillem Borrell i Nogueras wrote:
> I wrote the next function just to learn how ctypes work with numpy arrays. I
> am not trying to write yet another wrapper to lapack, it's just an
> experiment. (you can cut and paste the code)
>
> from ctypes import c_int
> from numpy import array,float64
> from numpy.ctypeslib import load_library,ndpointer
>
> def dgesv(N,A,B):
> # A=array([[1,2],[3,4]],dtype=float64,order='FORTRAN')
> # B=array([1,2],dtype=float64,order='FORTRAN')
Here, I'd use something like
A = asfortranarray(A.astype(float64))
B = asfortranarray(B.astype(float64))
> cN=c_int(N)
> NRHS=c_int(1)
> LDA=c_int(N)
> IPIV=(c_int * N)()
> LDB=c_int(N)
> INFO=c_int(1)
>
> lapack=load_library('liblapack.so','/usr/lib/')
>
> lapack.argtypes=[c_int,c_int,
> ndpointer(dtype=float64,
> ndim=2,
> flags='FORTRAN'),
> c_int,c_int,
> ndpointer(dtype=float64,
> ndim=1,
> flags='FORTRAN'),
> c_int,c_int]
This should be lapack.dgesv_.argtypes.
Cheers
Stéfan
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