source: proiecte/pmake3d/make3d_original/Make3dSingleImageStanford_version0.1/third_party/local_ext_mod/lmax.m @ 37

function [lmval,indd]=lmax(xx,filt)
%LMAX   [lmval, indd]=lmax(xx,filt). Find local maxima in vector XX,where
%       LMVAL is the output vector with maxima values, INDD  is the 
%       corresponding indexes, FILT is the number of passes of the small
%       running average filter in order to get rid of small peaks.  Default
%       value FILT =0 (no filtering). FILT in the range from 1 to 3 is 
%       usially sufficient to remove most of a small peaks
%       For example:
%       xx=0:0.01:35; y=sin(xx) + cos(xx ./3); 
%       plot(xx,y); grid; hold on;
%       [b,a]=lmax(y,2)
%        plot(xx(a),y(a),'r+')
%       see also LMIN, MAX, MIN
        
%**************************************************|
%       Serge Koptenko, Guigne International Ltd., |
%       phone (709)895-3819, fax (709)895-3822     |
%--------------06/03/97----------------------------|

x=xx;
len_x = length(x);
        fltr=[1 1 1]/3;
  if nargin <2, filt=0; 
        else
x1=x(1); x2=x(len_x); 
        for jj=1:filt,
        c=conv(fltr,x);
        x=c(2:len_x+1);
        x(1)=x1;  
        x(len_x)=x2; 
        end
  end
lmval=[]; indd=[];
i=2;            % start at second data point in time series
    while i < len_x-1,
        if x(i) > x(i-1)
           if x(i) > x(i+1)     % definite max
lmval =[lmval x(i)];
indd = [ indd i];
           elseif x(i)==x(i+1)&x(i)==x(i+2)     % 'long' flat spot
%lmval =[lmval x(i)];   %1   comment these two lines for strict case
%indd = [ indd i];      %2 when only  definite max included
i = i + 2;              % skip 2 points
           elseif x(i)==x(i+1)  % 'short' flat spot
%lmval =[lmval x(i)];   %1   comment these two lines for strict case
%indd = [ indd i];      %2 when only  definite max included
i = i + 1;              % skip one point
           end
        end
        i = i + 1;
    end
if filt>0 & ~isempty(indd),
        if (indd(1)<= 3)|(indd(length(indd))+2>length(xx)), 
           rng=1;       %check if index too close to the edge
        else rng=2;
        end
          for ii=1:length(indd),        % Find the real maximum value
            [val(ii) iind(ii)] = max(xx(indd(ii) -rng:indd(ii) +rng));
            iind(ii)=indd(ii) + iind(ii)  -rng-1;
          end
  indd=iind; lmval=val;
else
end