/usr/share/freemat/toolbox/signal/hilbert.m is in freemat-data 4.0-5.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 | % HILBERT HILBERT Hilbert Transform
%
% Usage
%
% The hilbert function computes the hilbert transform of the argument
% vector or matrix. The FreeMat hilbert function is compatible with
% the one from the MATLAB API. This means that the output of the
% hilbert function is the sum of the original function and an
% imaginary signal containing the Hilbert transform of it. There are
% two syntaxes for the hilbert function. The first is
%
% y = hilbert(x)
%
% where x is real vector or matrix. If x is a matrix, then he
% Hilbert transform is computed along the columns of x. The
% second syntax provides a dimension along which to take the
% transform.
%
% y = hilbert(x,n)
%
% where n is the dimension along which to apply the transformation.
% Copyright (c) 2002-2007 Samit Basu
% Licensed under the GPL
function y = hilbert(x,n)
[t,ns] = shiftdim(x);
if (nargin == 1)
n = size(t,1);
end
f = fft(t,n,1);
h = zeros(n,1);
h(1) = 1;
if (rem(n,2) == 0)
h((n/2)+1) = 1;
h(2:(n/2)) = 2;
else
h(2:((n+1)/2)) = 2;
end
y = ifft(f.*repmat(h,1,size(f,2)));
y = shiftdim(y,-ns);
|