[SciPy-user] scipy.basic to numpy
Rob Managan
managan at llnl.gov
Thu Jan 5 17:19:45 EST 2006
At 2:22 PM -0600 1/5/06, Pearu Peterson wrote:
> > On Jan 5, 2006, at 4:03 PM, Travis Oliphant wrote:
>>
> >> Please re-send any bug reports regarding fft on OSX.
>>
>
>What is the output of
>
> scipy.show_config()
>
>?
>
>Pearu
[mangrove:~/Documents/devel/scipy] managan% python
Python 2.4.1 (#2, Mar 31 2005, 00:05:10)
[GCC 3.3 20030304 (Apple Computer, Inc. build 1666)] on darwin
Type "help", "copyright", "credits" or "license" for more information.
>>> import scipy
>>> scipy.show_config()
lapack_opt_info:
extra_link_args = ['-Wl,-framework', '-Wl,Accelerate']
extra_compile_args = ['-faltivec']
define_macros = [('NO_ATLAS_INFO', 3)]
blas_opt_info:
extra_link_args = ['-Wl,-framework', '-Wl,Accelerate']
extra_compile_args = ['-faltivec',
'-I/System/Library/Frameworks/vecLib.framework/Headers']
define_macros = [('NO_ATLAS_INFO', 3)]
djbfft_info:
NOT AVAILABLE
fftw_info:
libraries = ['rfftw', 'fftw']
library_dirs = ['/Users/managan/Documents/local/lib']
define_macros = [('SCIPY_FFTW_H', None)]
include_dirs = ['/Users/managan/Documents/local/include']
******
Here is the basic error I see
******
>>> import numpy
>>> x = numpy.arange(16)*2*numpy.pi/16.0
>>> sx = numpy.sin(x)
>>> sx
array([ 0.00000000e+00, 3.82683432e-01, 7.07106781e-01,
9.23879533e-01, 1.00000000e+00, 9.23879533e-01,
7.07106781e-01, 3.82683432e-01, 1.22464680e-16,
-3.82683432e-01, -7.07106781e-01, -9.23879533e-01,
-1.00000000e+00, -9.23879533e-01, -7.07106781e-01,
-3.82683432e-01])
>>> scipy.fft(sx)
array([ 1.77975831e-16 +0.00000000e+00j,
-1.36807534e-15 -8.00000000e+00j,
-3.87815369e-16 -8.43346956e-16j,
1.91553812e-16 -1.08399892e-15j,
1.14423775e-17 -4.99600361e-16j,
1.91553812e-16 -1.95820501e-16j,
6.32744729e-16 -1.77213142e-16j,
4.95108994e-16 +0.00000000e+00j,
2.88998134e-16 +0.00000000e+00j,
4.95108994e-16 -0.00000000e+00j,
6.32744729e-16 +1.77213142e-16j,
1.91553812e-16 +1.95820501e-16j,
1.14423775e-17 +4.99600361e-16j,
1.91553812e-16 +1.08399892e-15j,
-3.87815369e-16 +8.43346956e-16j, -1.36807534e-15 +8.00000000e+00j])
>>> scipy.ifft(scipy.fft(sx))
array([ 2.46519033e-32+0.j, -3.12314248e-16-0.j, -8.32667268e-17-0.j,
-5.85949503e-18-0.j, 0.00000000e+00-0.j, 1.72392949e-16-0.j,
1.38777878e-16-0.j, 1.18025219e-16-0.j, 1.22464680e-16+0.j,
1.18025219e-16+0.j, 1.38777878e-16+0.j, 1.72392949e-16+0.j,
0.00000000e+00+0.j, -5.85949503e-18+0.j, -8.32667268e-17+0.j,
-3.12314248e-16+0.j])
>>> numpy.ifft(numpy.fft(sx))
array([ 6.16297582e-32 +0.00000000e+00j,
3.82683432e-01 +0.00000000e+00j,
7.07106781e-01 -5.55111512e-17j,
9.23879533e-01 +1.23259516e-32j,
1.00000000e+00 -2.46519033e-32j,
9.23879533e-01 +0.00000000e+00j,
7.07106781e-01 -5.55111512e-17j,
3.82683432e-01 -1.23259516e-32j,
1.22464680e-16 +0.00000000e+00j,
-3.82683432e-01 +0.00000000e+00j,
-7.07106781e-01 +5.55111512e-17j,
-9.23879533e-01 +1.23259516e-32j,
-1.00000000e+00 +2.46519033e-32j,
-9.23879533e-01 +0.00000000e+00j,
-7.07106781e-01 +5.55111512e-17j, -3.82683432e-01 -1.23259516e-32j])
The real parts of the last two should agree but scipy gives zeros to
within roundoff.
--
*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-
Rob Managan email managan at llnl.gov
LLNL phone: 925-423-0903
P.O. Box 808, L-095 FAX: 925-422-3389
Livermore, CA 94551-0808
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