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// Scilab ( http://www.scilab.org/ ) - This file is part of Scilab
// Copyright (C) ???? - INRIA - Scilab
//
// This file must be used under the terms of the CeCILL.
// This source file is licensed as described in the file COPYING, which
// you should have received as part of this distribution. The terms
// are also available at
// http://www.cecill.info/licences/Licence_CeCILL_V2.1-en.txt
function mapsound (w,dt,fmin,fmax,simpl,rate)
// Plots a sound map for a sound.
// It does FFT at time increments dt.
// rate is the sampling rate.
// simpl points are collected for speed reasons.
[lhs,rhs]=argn(0);
if ( rhs <= 5 ) then rate=0;end
if ( rhs <= 4 ) then simpl=1; end ;
if ( rhs <= 3 ) then fmax=1500; end ;
if ( rhs <= 2 ) then fmin=100; end ;
if ( rhs <= 1 ) then dt=0.1; end ;
n=prod(size(w));
defaultrate=22050;
if rate==0; rate=defaultrate; end;
dp=dt*rate;
points=2^floor(log(dp)/log(2));
ind=fmin/rate*points/simpl:fmax/rate*points/simpl;
f=abs(fft(w(1:points),1));
f=sum(matrix(f,points/simpl,simpl),"c")';
M=f(ind);
i=1;
i=i+dp;
while i+points <= n;
f=abs(fft(w(i:i+points-1),1));
f=sum(matrix(f,points/simpl,simpl),"c")';
M=[M;f(ind)];
i=i+dp;
end;
[nl,nc]=size(M);
if nl==1 ; return;end
x_abs= (0:(nl-1))*(n/rate)/(nl-1);
y_abs= (0:(nc-1))/(nc-1);
y_abs= fmin*(1-y_abs) + fmax*(y_abs)
grayplot(x_abs,y_abs,-M)
endfunction
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