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See the recommended documentation of this function
fftw_flags
set computation method of fast fourier transform of the fftw function
Calling Sequence
[a,[S]]=fftw_flags([x1;x2;...])
Arguments
- [x1;x2;...]
Matrix of string or integers. Entry to switch the method of fft computation for fftw.
- a
Integer. Give the current value of the flag of the fftw function.
- S
String matrix. Give the string value of the fftw flag.
Description
This function enables the change of the unsigned
flags
parameter of the
fftw_plan_guru_split_dft
function that is used in fftw function.
Default value is FFTW_ESTIMATE
Accepted entries are :
FFTW_MEASURE or 0
FFTW_DESTROY_INPUT or 1
FFTW_UNALIGNED or 2
FFTW_CONSERVE_MEMORY or 4
FFTW_EXHAUSTIVE or 8
FFTW_PRESERVE_INPUT or 16
FFTW_PATIENT or 32
FFTW_ESTIMATE or 64
FFTW_ESTIMATE_PATIENT or 128
FFTW_BELIEVE_PCOST or 256
FFTW_NO_DFT_R2HC or 512
FFTW_NO_NONTHREADED or 1024
FFTW_NO_BUFFERING or 2048
FFTW_NO_INDIRECT_OP or 4096
FFTW_ALLOW_LARGE_GENERIC or 8192
FFTW_NO_RANK_SPLITS or 16384
FFTW_NO_VRANK_SPLITS or 32768
FFTW_NO_VRECURSE or 65536
FFTW_NO_SIMD or 131072
FFTW_NO_SLOW or 262144
FFTW_NO_FIXED_RADIX_LARGE_N or 524288
FFTW_ALLOW_PRUNING or 1048576
Rmk : when using FFTW_MEASURE/FFTW_PATIENT/FFTW_EXHAUSTIVE you must call two times fftw. (first call for initialisation, second and others calls for computation)
Examples
//return the integer value of the flag fftw_flags() //change flags fftw_flags(["FFTW_MEASURE";"FFTW_CONSERVE_MEMORY"]); //change flags and display current value of fftw flags (both integer and strings) [a,S]=fftw_flags("FFTW_PATIENT")
See Also
<< fftw | FFTW | fftw_forget_wisdom >> |