fnn_ml2.m

空间统计工具箱

function tnnmat=fnn_ml2(xcoord, ycoord, m, n, istart)
%
%fnn_ml2(xcoord, ycoord, m, n, istart)
%
%This function computes m spatiotemporal nearest neighbors for each observation from observation 1 to (n-istart).
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%INPUT:
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%xcoord, ycoord are n by 1 vectors ordered by time with observation 1 the most recent and observation n the oldest.
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%m is the number of nearest neighbors previous in time
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%n is the number of observations
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%istart is where to begin computing temporal nearest neighbors. This allows istart observations to exist before beginning, 
%and istart>m.
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%OUTPUT:
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%tnnmat is a n by m matrix of spatiotemporal nearest neighbors.
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%NOTES:
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%There is a fortran mex version of a similar function, and it runs faster. This function will be acceptably fast for moderate sample sizes
%in version 6.5 due to the JIT compiler.
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%This function requires more or n-squared memory locations, and hence will not work for large n.
%
%A similar function was used in:
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%Pace, R. Kelley and Ronald Barry, O.W. Gilley, C.F. Sirmans, 
%揂 Method for Spatial-temporal Forecasting with an Application to Real Estate Prices,