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Diffstat (limited to 'macros/fftshift1.sci')
| -rw-r--r-- | macros/fftshift1.sci | 21 |
1 files changed, 21 insertions, 0 deletions
diff --git a/macros/fftshift1.sci b/macros/fftshift1.sci index 2928850..d8721cd 100644 --- a/macros/fftshift1.sci +++ b/macros/fftshift1.sci @@ -1,4 +1,25 @@ function y= fftshift1(X,DIM) +//Perform a shift of the vector X, for use with the 'fft' and 'ifft' functions, in order the move the frequency 0 to the center of the vector or matrix. +//Calling Sequence +// fftshift1 (X) +// fftshift1 (X, DIM) +//Parameters +//X:It is a vector of N elements corresponding to time samples +//DIM: The optional DIM argument can be used to limit the dimension along which the permutation occurs +//Description +//This is an Octave function. +//Perform a shift of the vector X, for use with the 'fft' and 'ifft' functions, in order the move the frequency 0 to the center of the vector or matrix. +// +//If X is a vector of N elements corresponding to N time samples spaced by dt, then 'fftshift1 (fft (X))' corresponds to frequencies +// +//f = [ -(ceil((N-1)/2):-1:1)*df 0 (1:floor((N-1)/2))*df ] +// +//where df = 1 / dt. +// +//If X is a matrix, the same holds for rows and columns. If X is an array, then the same holds along each dimension. +// +//The optional DIM argument can be used to limit the dimension along + which the permutation occurs. rhs= argn(2); if(rhs <1 | rhs >2) error('Wrong number of Input arguments'); |