[Numpy-discussion] fourier with single precision

2007-08-01 Thread Lars Friedrich
Hello, is there a way to tell numpy.fft.fft2 to use complex64 instead of complex128 as output dtype to speed the up transformation? Thanks Lars ___ Numpy-discussion mailing list Numpy-discussion@scipy.org http://projects.scipy.org/mailman/listinfo/nump

Re: [Numpy-discussion] fourier with single precision

2007-08-01 Thread David Cournapeau
Lars Friedrich wrote: > Hello, > > is there a way to tell numpy.fft.fft2 to use complex64 instead of > complex128 as output dtype to speed the up transformation? > As far as I can read from the fft code in numpy, only double is supported at the moment, unfortunately. Note that you can get some

Re: [Numpy-discussion] fourier with single precision

2007-08-02 Thread Lars Friedrich
Hello, David Cournapeau wrote: > As far as I can read from the fft code in numpy, only double is > supported at the moment, unfortunately. Note that you can get some speed > by using scipy.fftpack methods instead, if scipy is an option for you. What I understood is that numpy uses FFTPACK's alg

Re: [Numpy-discussion] fourier with single precision

2007-08-02 Thread Warren Focke
On Thu, 2 Aug 2007, Lars Friedrich wrote: > What I understood is that numpy uses FFTPACK's algorithms. Sort of. It appears to be a hand translation from F77 to C. > From www.netlib.org/fftpack (is this the right address?) I took that > there is a single-precision and double-precision-version

Re: [Numpy-discussion] fourier with single precision

2007-08-02 Thread Charles R Harris
On 8/2/07, Warren Focke <[EMAIL PROTECTED]> wrote: > > > > On Thu, 2 Aug 2007, Lars Friedrich wrote: > > > What I understood is that numpy uses FFTPACK's algorithms. > > Sort of. It appears to be a hand translation from F77 to C. > > > From www.netlib.org/fftpack (is this the right address?) I too

Re: [Numpy-discussion] fourier with single precision

2007-08-02 Thread Warren Focke
On Thu, 2 Aug 2007, Charles R Harris wrote: > On X86 machines the main virtue would be smaller and more cache friendly > arrays because double precision arithmetic is about the same speed as single > precision, sometimes even a bit faster. The PPC architecture does have > faster single than doub

Re: [Numpy-discussion] fourier with single precision

2007-08-03 Thread Warren Focke
On Thu, 2 Aug 2007, Warren Focke wrote: > > > On Thu, 2 Aug 2007, Lars Friedrich wrote: > >> versions to numpy? I am not a decent C-hacker, but if someone tells me, >> that this task is not *too* hard, I would start looking more closely at the >> code... > > It shouldn't be hard. fftpack.c wil

Re: [Numpy-discussion] fourier with single precision

2007-08-05 Thread Lars Friedrich
Hello, thanks for your comments. If I got you right, I should look for a FFT-code that uses SSE (what does this actually stand for?), which means that it vectorizes 32bit-single-operations into larger chunks that make efficient use of recent CPUs. You mentioned FFTW and MKL. Is this www.fftw.o

Re: [Numpy-discussion] fourier with single precision

2007-08-06 Thread Nils Wagner
Lars Friedrich wrote: > Hello, > > thanks for your comments. If I got you right, I should look for a > FFT-code that uses SSE (what does this actually stand for?), which means > that it vectorizes 32bit-single-operations into larger chunks that make > efficient use of recent CPUs. > > http://

Re: [Numpy-discussion] fourier with single precision

2007-08-06 Thread David Cournapeau
Lars Friedrich wrote: > Hello, > > thanks for your comments. If I got you right, I should look for a > FFT-code that uses SSE (what does this actually stand for?), which means > that it vectorizes 32bit-single-operations into larger chunks that make > efficient use of recent CPUs. > > You mentio

Re: [Numpy-discussion] fourier with single precision

2007-08-06 Thread Matthieu Brucher
> > MKL is from Intel (free as in beer on Linux and for academic purpose I > think, but of course, you should check whether this applies to you). AFAIK, the MKL is free for non-commercial purposes under Linux only, and there is a special license for academics. Matthieu __

Re: [Numpy-discussion] fourier with single precision

2007-08-06 Thread David Cournapeau
Lars Friedrich wrote: > Hello, > > thanks for your comments. If I got you right, I should look for a > FFT-code that uses SSE (what does this actually stand for?), which means > that it vectorizes 32bit-single-operations into larger chunks that make > efficient use of recent CPUs. > > You mentio

Re: [Numpy-discussion] fourier with single precision

2007-08-07 Thread Lars Friedrich
Thank you for your comments! I will try this fftw3-scipy approach and see how much faster I can get. Maybe this is enough for me...? Lars ___ Numpy-discussion mailing list Numpy-discussion@scipy.org http://projects.scipy.org/mailman/listinfo/numpy-disc