lagcor.m

本文件夹中包含了克立格插值

function [lagcor] = lagcor(field, index, lag);

% HEADER_START
%
% NAME:  lagcor
%
% DESCRIPTION:
%
%   Computes (lag) correlations between a field and a time series without NaNs
%
% REQUIRED_ARGS: 
%
%   field: 3D array time x lat x lon)
%   index: 1D array providing the time series to be correlated with field 
%   lag: :  positive number
% 
%
% OPTIONAL_ARGS: 
%
%   lag: +ve/-ve number. If > 0 then field lags index otherwise index lags
%         field. 
%
% OUTPUT_ARGS: 
%
%   lagcor: lat x lon array containing the lagged correlations
%
% COMMENTS:
%
%    No NaNs allowed
%
% USAGE:
%
%   example:   field = rand(10, 3, 5); index = rand(10,1); 
%               cor = lagcor(field, index, 1);
% 
% AUTHOR:
% 
%   [e-mail],
%   [e-mail], July 2003.
%
% HISTORY: Sep 2004
%
% HEADER_END
%


siz = size(field);
ti = siz(1); la = siz(2) ; lo = siz(3);
field1=reshape(newfield, ti,la*lo);


 if (lag >= 0)
   dsip('fields lags index')
   newindex = index(lag+1:ti);
   newfield = field(1:ti-lag,:);
 else
   dsip('index lags field')
   lag = -lag;
   newindex = index(1:ti-lag);
   newfield = field(lag+1:ti,:);
 end

lagcor = [];

for k = 1:la*lo;
    x = field1(:,k);
    xx = corrcoef(x,newindex);
    lagcor(k) = xx(2);
end

 lagcor = reshape(lagcor,la,lo);