weim

 weim - Running weighted average of input data given a window

 USAGE:
 function [y,w]=weim(N,wt,x)

 DESCRIPTION:
 it computes a weighted average using the window function
 this filter is designed for odd weight numbers only

 INPUT:
 N is numbers of weights
 wt is the shape of the desired window (see window.m)
 x is the input data

 OUTPUT:
  y: Smoothed data vector
  w: The window used for smoothing (from window.m)

 SEE ALSO:
  window.m

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0001 function [y,w]=weim(N,wt,x)
0002 % weim - Running weighted average of input data given a window
0003 %
0004 % USAGE:
0005 % function [y,w]=weim(N,wt,x)
0006 %
0007 % DESCRIPTION:
0008 % it computes a weighted average using the window function
0009 % this filter is designed for odd weight numbers only
0010 %
0011 % INPUT:
0012 % N is numbers of weights
0013 % wt is the shape of the desired window (see window.m)
0014 % x is the input data
0015 %
0016 % OUTPUT:
0017 %  y: Smoothed data vector
0018 %  w: The window used for smoothing (from window.m)
0019 %
0020 % SEE ALSO:
0021 %  window.m
0022 %
0023 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
0024 w=window(N,wt);
0025 
0026 r=size(x);
0027 if r(1) > 1, x=x'; end
0028 
0029 ln=(N-1)/2;
0030 lx=length(x);
0031 lf=lx-ln+1;
0032 y=zeros(size(x));
0033 
0034 for i=1:lx,
0035 
0036   if i <= ln,
0037   
0038        y(i)=sum(x(1:ln+i).*w(ln+2-i:N))/sum(w(ln+2-i:N));
0039   
0040   elseif ((i > ln) & (i < lf)),
0041   
0042        y(i)=sum(x(i-ln:i+ln).*w)/sum(w);
0043 
0044   else  % i >=lf
0045 
0046        y(i)=sum(x(i-ln:lx).*w(1:length(i-ln:lx)))/sum(w(1:length(i-ln:lx)));
0047 
0048   end
0049 end
0050 return
0051