view aim-mat/tools/@signal/logsigx.m @ 0:74dedb26614d

Initial checkin of AIM-MAT version 1.5 (6.4.2011).

% method of class @signal
% 
%   INPUT VALUES:
%  
%   RETURN VALUE:
%
% 
% (c) 2003-2008, University of Cambridge, Medical Research Council 
% Maintained by Tom Walters ([e-mail]), written by Stefan Bleeck ([e-mail])
% http://www.pdn.cam.ac.uk/cnbh/aim2006
% $Date: 2008-06-10 18:00:16 +0100 (Tue, 10 Jun 2008) $
% $Revision: 585 $

function [lsig,scaleinfo]=logsigx(sig,tmin,tmax,nr_points)
% usage: [lsig,scaler]=logsigx(sig,tmin,tmax,nr_points)
% transferes the signal to a signal that is in logarithmic scale
% so plotting the original signal logarithmic is identical to
% plot the transfered signal linear
% uses only the part of the signal between tmin and tmax
%
% reverse operation: linsigx(sig,tmin,tmax,nr_points)


if nargin < 4
    nr_points=getnrpoints(sig);
end
if nargin<3
    tmax=getmaximumtime(sig);
end
if nargin<2
    tmin=getminimumtime(sig);
end
if tmin==0
    tmin=1/getsr(sig);
end


oldvals=getvalues(sig);
newvals=zeros(nr_points,1);


[ntimes,scaleinfo]=distributelogarithmic(tmin,tmax,nr_points);
newvals=gettimevalue(sig,ntimes);
if isnan(newvals(1))
    newvals(1)=0;
end

lsig=sig;    % copy all values
lsig=setvalues(lsig,newvals,1);

lsig=setnrxticks(lsig,6);
l=distributelogarithmic(tmin,tmax,6);

l=round(l*10000)/10;

lsig=setxlabels(lsig,l);