diff options
Diffstat (limited to 'flow/gsl/gsl.3')
| -rw-r--r-- | flow/gsl/gsl.3 | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/flow/gsl/gsl.3 b/flow/gsl/gsl.3 index cd7eb8b..21a25d2 100644 --- a/flow/gsl/gsl.3 +++ b/flow/gsl/gsl.3 @@ -457,7 +457,7 @@ Real sample values [0..n_values-1] Complex frequency values [0..n_values-1] .PD 1 .PP -Real valued variant of \fBgsl_power2_fftac()\fP, the input array tqcontains real valued equidistant sampled data [0..n_values-1], and the output array tqcontains the positive frequency half of the complex valued fourier transform. Note, that the complex valued fourier transform H of a purely real valued set of data, satisfies \fBH(-f)\fP = Conj(\fBH(f)\fP), where \fBConj()\fP denotes the complex conjugate, so that just the positive frequency half suffices to describe the entire frequency spectrum. Even so, the resulting n_values/2 complex frequencies are one value off in storage size, but the resulting frequencies \fBH(0)\fP and \fBH(n_values/2)\fP are both real valued, so the real portion of \fBH(n_values/2)\fP is stored in ri_values_out[1] (the imaginery part of \fBH(0)\fP), so that both r_values_in and ri_values_out can be of size n_values. Note that the transformation is performed out of place, the input array is not modified, and may not overlap with the output array. +Real valued variant of \fBgsl_power2_fftac()\fP, the input array contains real valued equidistant sampled data [0..n_values-1], and the output array contains the positive frequency half of the complex valued fourier transform. Note, that the complex valued fourier transform H of a purely real valued set of data, satisfies \fBH(-f)\fP = Conj(\fBH(f)\fP), where \fBConj()\fP denotes the complex conjugate, so that just the positive frequency half suffices to describe the entire frequency spectrum. Even so, the resulting n_values/2 complex frequencies are one value off in storage size, but the resulting frequencies \fBH(0)\fP and \fBH(n_values/2)\fP are both real valued, so the real portion of \fBH(n_values/2)\fP is stored in ri_values_out[1] (the imaginery part of \fBH(0)\fP), so that both r_values_in and ri_values_out can be of size n_values. Note that the transformation is performed out of place, the input array is not modified, and may not overlap with the output array. .PD .SS \fBgsl_power2_fftsr\fP (\fIn_values\fP, \fIri_values_in\fP, \fIr_values_out\fP); .PD 0 |