Xplor-NIH: module fft

fft

Fast Fourier Transform module - wrapper for FFTPACK The following functions are defined fft(v) - return the complex FFT of v fft_inv(v) - return the complex inverse FFT of rfft(v) - return the real FFT of v rfft_inv(v) - return the real inverse FFT of v These functions call methods of the following objects default_fft and default_rfft, which are instances of FFT_CLASS and RFFT_CLASS classes, respectively. Initialization for a particular length fft is performed when a different size sequence v is supplied. If taking FFTs of sequences with differing sizes, instantiate separate FFT_CLASS objects for each size. The transforms are not normalized. To obtain a normalized transform the output must be divided by len(v). The algorithms used are: N=len(v) --> forward complex transform for j=0,...,N-1 c[j]=the sum from k=0,...,N-1 of v[k]*exp(-i*j*k*2*pi/N) where i=sqrt(-1) --> inverse complex transform for j=0,...,N-1 c[j]=the sum from k=0,...,N-1 of v[k]*exp(i*j*k*2*pi/N) where i=sqrt(-1) --> forward real transform r[0] = the sum from n=0 to n=N-1 of v[n] if N is even set L = N/2-1 , if N is odd set L = (N-1)/2 then for m = 1,...,L r[2*m-1] = the sum from n = 0 to n = N-1 of v[n]*cos(m*n*2*pi/N) r[2*m] = the sum from n = 1 to n = N-1 of -v[n]*sin(m*n*2*pi/N) if N is even r[N-1] = the sum from n = 0 to n = N-1 of (-1)**(n)*v[n] --> inverse real transform for N even and for n = 0,...,N-1 r[n] = v[0]+(-1)**(N-1)*v[N-1] plus the sum from m=1 to m=N/2-1 of 2.*v[2*m-1]*cos(m*n*2*pi/N) -2.*v[2*m ]*sin(m*n*2*pi/N) for N odd and for n = 0,...,N-1 r[n] = v[0] plus the sum from m=1 to m=(N-1)/2 of 2.*v[2*m-1]*cos(m*n*2*pi/N) -2.*v[2*m ]*sin(m*n*2*pi/N) # This file was created automatically by SWIG. # Don't modify this file, modify the SWIG interface instead. # This file is compatible with both classic and new-style classes.

Classes



__builtin__.object

CDSVector_DComplex

CDSVector_DComplexPtr

FFT_FLOATTYPE

FFT_FLOATTYPEPtr

FFT_FLOATTYPE

FFT_FLOATTYPEPtr

RFFT_FLOATTYPE

RFFT_FLOATTYPEPtr

RFFT_FLOATTYPE

RFFT_FLOATTYPEPtr

class CDSVector_DComplex(__builtin__.object)



Methods defined here:

__add__(*args)

__del__(self, destroy=<built-in function delete_CDSVector_DComplex>)

__div__(*args)

__getattr__ lambda self, name

__getitem__(*args)

__getslice__(*args)

__iadd__(*args)

__idiv__(*args)

__imul__(*args)

__init__(self, *args)

__isub__(*args)

__len__(*args)

__mul__(*args)

__neg__(*args)

__pow__(*args)

__repr__(self)

__rmul__(*args)

__setattr__ lambda self, name, value

__setitem__(*args)

__str__(*args)

__sub__(*args)

fromList(s, l)

help(*args)

resize(*args)

scale(*args)

set(*args)

Data and other attributes defined here:

__dict__ = <dictproxy object at 0x25487c0>
dictionary for instance variables (if defined)

__swig_getmethods__ = {}

__swig_setmethods__ = {}

__weakref__ = <attribute '__weakref__' of 'CDSVector_DComplex' objects>
list of weak references to the object (if defined)

class CDSVector_DComplexPtr(CDSVector_DComplex)



Method resolution order:

CDSVector_DComplexPtr

CDSVector_DComplex

__builtin__.object

Methods defined here:

__init__(self, this)

Methods inherited from CDSVector_DComplex:

__add__(*args)

__del__(self, destroy=<built-in function delete_CDSVector_DComplex>)

__div__(*args)

__getattr__ lambda self, name

__getitem__(*args)

__getslice__(*args)

__iadd__(*args)

__idiv__(*args)

__imul__(*args)

__isub__(*args)

__len__(*args)

__mul__(*args)

__neg__(*args)

__pow__(*args)

__repr__(self)

__rmul__(*args)

__setattr__ lambda self, name, value

__setitem__(*args)

__str__(*args)

__sub__(*args)

fromList(s, l)

help(*args)

resize(*args)

scale(*args)

set(*args)

Data and other attributes inherited from CDSVector_DComplex:

__dict__ = <dictproxy object at 0x2548750>
dictionary for instance variables (if defined)

__swig_getmethods__ = {}

__swig_setmethods__ = {}

__weakref__ = <attribute '__weakref__' of 'CDSVector_DComplex' objects>
list of weak references to the object (if defined)

FFT = class FFT_FLOATTYPE(__builtin__.object)



Methods defined here:

__del__(self, destroy=<built-in function delete_FFT_FLOATTYPE>)

__getattr__ lambda self, name

__init__(self, *args)

__repr__(self)

__setattr__ lambda self, name, value

fft(*args)

fft_inv(*args)

resize(*args)

Data and other attributes defined here:

__dict__ = <dictproxy object at 0x25489f0>
dictionary for instance variables (if defined)

__swig_getmethods__ = {}

__swig_setmethods__ = {}

__weakref__ = <attribute '__weakref__' of 'FFT_FLOATTYPE' objects>
list of weak references to the object (if defined)

class FFT_FLOATTYPE(__builtin__.object)



Methods defined here:

__del__(self, destroy=<built-in function delete_FFT_FLOATTYPE>)

__getattr__ lambda self, name

__init__(self, *args)

__repr__(self)

__setattr__ lambda self, name, value

fft(*args)

fft_inv(*args)

resize(*args)

Data and other attributes defined here:

__dict__ = <dictproxy object at 0x25488d8>
dictionary for instance variables (if defined)

__swig_getmethods__ = {}

__swig_setmethods__ = {}

__weakref__ = <attribute '__weakref__' of 'FFT_FLOATTYPE' objects>
list of weak references to the object (if defined)

class FFT_FLOATTYPEPtr(FFT_FLOATTYPE)



Method resolution order:

FFT_FLOATTYPEPtr

FFT_FLOATTYPE

__builtin__.object

Methods defined here:

__init__(self, this)

Methods inherited from FFT_FLOATTYPE:

__del__(self, destroy=<built-in function delete_FFT_FLOATTYPE>)

__getattr__ lambda self, name

__repr__(self)

__setattr__ lambda self, name, value

fft(*args)

fft_inv(*args)

resize(*args)

Data and other attributes inherited from FFT_FLOATTYPE:

__dict__ = <dictproxy object at 0x2548a98>
dictionary for instance variables (if defined)

__swig_getmethods__ = {}

__swig_setmethods__ = {}

__weakref__ = <attribute '__weakref__' of 'FFT_FLOATTYPE' objects>
list of weak references to the object (if defined)

RFFT = class RFFT_FLOATTYPE(__builtin__.object)



Methods defined here:

__del__(self, destroy=<built-in function delete_RFFT_FLOATTYPE>)

__getattr__ lambda self, name

__init__(self, *args)

__repr__(self)

__setattr__ lambda self, name, value

fft(*args)

fft_inv(*args)

resize(*args)

Data and other attributes defined here:

__dict__ = <dictproxy object at 0x25484e8>
dictionary for instance variables (if defined)

__swig_getmethods__ = {}

__swig_setmethods__ = {}

__weakref__ = <attribute '__weakref__' of 'RFFT_FLOATTYPE' objects>
list of weak references to the object (if defined)

class RFFT_FLOATTYPE(__builtin__.object)



Methods defined here:

__del__(self, destroy=<built-in function delete_RFFT_FLOATTYPE>)

__getattr__ lambda self, name

__init__(self, *args)

__repr__(self)

__setattr__ lambda self, name, value

fft(*args)

fft_inv(*args)

resize(*args)

Data and other attributes defined here:

__dict__ = <dictproxy object at 0x25488a0>
dictionary for instance variables (if defined)

__swig_getmethods__ = {}

__swig_setmethods__ = {}

__weakref__ = <attribute '__weakref__' of 'RFFT_FLOATTYPE' objects>
list of weak references to the object (if defined)

class RFFT_FLOATTYPEPtr(RFFT_FLOATTYPE)



Method resolution order:

RFFT_FLOATTYPEPtr

RFFT_FLOATTYPE

__builtin__.object

Methods defined here:

__init__(self, this)

Methods inherited from RFFT_FLOATTYPE:

__del__(self, destroy=<built-in function delete_RFFT_FLOATTYPE>)

__getattr__ lambda self, name

__repr__(self)

__setattr__ lambda self, name, value

fft(*args)

fft_inv(*args)

resize(*args)

Data and other attributes inherited from RFFT_FLOATTYPE:

__dict__ = <dictproxy object at 0x2548980>
dictionary for instance variables (if defined)

__swig_getmethods__ = {}

__swig_setmethods__ = {}

__weakref__ = <attribute '__weakref__' of 'RFFT_FLOATTYPE' objects>
list of weak references to the object (if defined)

Functions

cat(...)

cat3(...)

cat4(...)

fft(*args) method of FFT_FLOATTYPE instance

fft_inv(*args) method of FFT_FLOATTYPE instance

help(...)

rfft = fft(*args) method of RFFT_FLOATTYPE instance

rfft_inv = fft_inv(*args) method of RFFT_FLOATTYPE instance

sum(...)

Data

FALSE = 0
PI = 3.1415926535897931
TRUE = 1
__package__ = None
__sthead_hh__ = 1
default_fft = <C CDS::FFT<(float_type)> instance at _905f050200000000_p_CDS__FFTTdouble_t>
default_rfft = <C CDS::RFFT<(float_type)> instance at _f030530200000000_p_CDS__RFFTTdouble_t>
pyXplorHelp = Type help() for interactive help, or help(object) for help about object.

Data
		FALSE = 0 PI = 3.1415926535897931 TRUE = 1 __package__ = None __sthead_hh__ = 1 default_fft = <C CDS::FFT<(float_type)> instance at _905f050200000000_p_CDS__FFTTdouble_t> default_rfft = <C CDS::RFFT<(float_type)> instance at _f030530200000000_p_CDS__RFFTTdouble_t> pyXplorHelp = Type help() for interactive help, or help(object) for help about object.