www.gusucode.com > stats 源码程序 matlab案例代码 > stats/SpecifyTheMahalanobisDistanceForNearestNeighborSearchExample.m

    %% Specify the Mahalanobis Distance for Nearest Neighbor Search
%%
% Load Fisher's iris data.  Focus on the petal dimensions.

% Copyright 2015 The MathWorks, Inc.

load fisheriris
X = meas(:,[3 4]); % Predictors
%%
% Prepare an exhaustive, nearest neighbors searcher. Specify to use the
% Mahalanobis distance metric.
Mdl = createns(X,'NSMethod','exhaustive','Distance','mahalanobis')
%%
% |Mdl| is an |ExhaustiveSearcher| model object.  Access properties of
% |Mdl| using dot notation. For example, use |Mdl.DistParameter| to
% access the Mahalanobis covariance parameter.
Mdl.DistParameter
%%
% You can pass query data and |Mdl| to:
%
% * <docid:stats_ug.buiwsyv knnsearch> to find indices and distances of nearest neighbors.
% * <docid:stats_ug.buiyhlh rangesearch> to find indices of all nearest neighbors
% within a distance that you specify.