images_to_heartpulses/fftfreq.m

32 lines
1001 B
Mathematica

## Copyright (C) 2023 Estevan
##
## This program is free software: you can redistribute it and/or modify
## it under the terms of the GNU General Public License as published by
## the Free Software Foundation, either version 3 of the License, or
## (at your option) any later version.
##
## This program is distributed in the hope that it will be useful,
## but WITHOUT ANY WARRANTY; without even the implied warranty of
## MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
## GNU General Public License for more details.
##
## You should have received a copy of the GNU General Public License
## along with this program. If not, see <https://www.gnu.org/licenses/>.
## -*- texinfo -*-
## @deftypefn {} {@var{retval} =} fftfreq (@var{input1}, @var{input2})
##
## @seealso{}
## @end deftypefn
## Author: Estevan <Estevan@BAISETAMEREDARR>
## Created: 2023-02-18
function f = fftfreq(n, dt)
if nargin < 2
dt = 1;
end
f = (0:n-1) / n;
f = fftshift(f);
f = f - floor(n/2) / n;
f = f / dt;