smooth.m

基于Matlab的地震数据处理显示和测井数据显示于处理的小程序

function avin=smooth(in,dist)
% Function computes average over "dist" samples of matrix "in". "dist" must be greater
% than or equal to 1, but need not be integer
% Written by: E. R.:
% Last updated: July 14, 2003: modified end condition to assure that mean of columns is not changed
%
%        avin=smooth(in,dist)
% INPUT
% in     matrix whose columns should be averaged
% dist   "distance" in terms of samples over which to average
% OUTPUT
% avout  matrix with averaged columns (same size as "in"). At both ends of the column
%        vectors the averaging is performed over fewer samples
% SEE ALSO: binsmooth
% EXAMPLE
%         a=[1,0,0,0,1,0,0,0,1]'
%         smooth(a,3)

if dist == 1
  avin=in;
  return
end

[n,m]=size(in);
if n == 1
  in=in';
  [n,m]=deal(m,n);
  flip=1;
else
  flip=0;
end
in=full(in);

%       Create an odd smoothing filter
idist=2*fix((dist-1)/2)+1;
xdist=dist-idist;

if xdist == 0
  weights=ones(dist,1)/dist;
else
  weights=ones(idist+2,1);
  weights([1,end])=0.5*xdist;
  weights=weights/dist;
end

if length(weights) > n
  avin=mean(in);
  avin=avin(ones(n,1),:);
  return
end

append=(length(weights)-1)/2;
avin=zeros(n,m);

for ii=1:size(in,2)
  temp1=conv(in(:,ii),weights);
  avin(:,ii)=temp1(append+1:end-append);
end

%       Repair wrong scaling at ends of data sets
for ii=1:append
  %fact=1/sum(weights(1:end-append-1+ii));
  %avin(ii,:)=avin(ii,:)*fact;
  %avin(end-ii+1,:)=avin(end-ii+1,:)*fact;
  fact=sum(weights(1:append+1-ii));
  avin(ii,:)=avin(ii,:)+in(ii,:)*fact;
  avin(end-ii+1,:)=avin(end-ii+1,:)+in(end-ii+1,:)*fact;
end

if flip
  avin=avin';
end