Mercurial > hg > camir-aes2014
diff toolboxes/MIRtoolbox1.3.2/somtoolbox/som_kmeanscolor.m @ 0:e9a9cd732c1e tip
first hg version after svn
author | wolffd |
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date | Tue, 10 Feb 2015 15:05:51 +0000 |
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--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/toolboxes/MIRtoolbox1.3.2/somtoolbox/som_kmeanscolor.m Tue Feb 10 15:05:51 2015 +0000 @@ -0,0 +1,139 @@ +function [color,best,kmeans]=som_kmeanscolor(sM,C,initRGB,contrast) + +% SOM_KMEANSCOLOR Map unit color code according to K-means clustering +% +% [color, best, kmeans] = som_kmeanscolor(sM, C, [initRGB],[contrast]) +% +% color = som_kmeanscolor(sM,15,som_colorcode(sM,'rgb1'),'enhance'); +% [color,best] = som_kmeanscolor(sM,15,[],'normal'); +% +% Input and output arguments ([]'s are optional): +% sM (struct) map struct +% C (scalar) maximum number of clusters +% initRGB (string, matrix) color code string accepted by SOM_COLORCODE +% or an Mx3 matrix of RGB triples, where M is the number +% of map units. Default: SOM_COLORCODEs default +% contrast (string) 'flat', 'enhanced' color contrast mode, default: +% 'enhanced' +% +% color (matrix) MxCx3 of RGB triples +% best (scalar) index for "best" clustering according to +% Davies-Boulding index; color(:,:,best) includes the +% corresponding color code. +% kmeans (cell) output of KMEANS_CLUSTERS in a cell array. +% +% The function gives a set of color codings according to K-means +% clustering. For clustering, it uses function KMEANS_CLUSTERS for map units, +% and it calculates color codings for 1,2,...,C clusters. +% The idea of coloring is that the color of a cluster is the mean of the +% original colors (RGB values) of the map units belonging to that cluster, +% see SOM_CLUSTERCOLOR. The original colors are defined by SOM_COLORCODE +% by default. Input 'contrast' simply specifies whether or not +% to linearly redistribute R,G, and B values so that minimum is 0 and +% maximum 1 ('enahanced') or to use directly the output of +% SOM_CLUSTERCOLOR ('flat'). KMEANS_CLUSTERS uses certain heuristics to +% select the best of 5 trials for each number of clusters. Evaluating the +% clustering multiple times may take some time. +% +% EXAMPLE +% +% load iris; % or any other map struct sM +% [color,b]=som_kmeanscolor(sM,10); +% som_show(sM,'color',color,'color',{color(:,:,b),'"Best clustering"'); +% +% See also SOM_SHOW, SOM_COLORCODE, SOM_CLUSTERCOLOR, KMEANS_CLUSTERS + +% Contributed to SOM Toolbox 2.0, April 1st, 2000 by Johan Himberg +% Copyright (c) by Johan Himberg +% http://www.cis.hut.fi/projects/somtoolbox/ + +% corrected help text 11032005 johan + +%%% Check number of inputs + +error(nargchk(2, 4, nargin)); % check no. of input args + +%%% Check input args & set defaults + +if isstruct(sM) & isfield(sM,'type') & strcmp(sM.type,'som_map'), + [tmp,lattice,msize]=vis_planeGetArgs(sM); + munits=prod(msize); + if length(msize)>2 + error('Does not work with 3D maps.') + end +else + error('Map struct requires for first input argument!'); +end + +if ~vis_valuetype(C,{'1x1'}), + error('Scalar value expect for maximum number of clusters.'); +end + +% check initial color coding +if nargin<3 | isempty(initRGB) + initRGB=som_colorcode(sM); +end + +% check contrast checking +if nargin<4 | isempty(contrast), + contrast='enhanced'; +end + +if ~ischar(contrast), + error('String input expected for input arg. ''contrast''.'); +else + switch lower(contrast) + case {'flat','enhanced'} + ; + otherwise + error(['''flat'' or ''enhanced'' expected for '... + 'input argument ''contrast''.']); + end +end + +if ischar(initRGB), + try + initRGB=som_colorcode(sM,initRGB); + catch + error(['Color code ' initRGB ... + 'was not recognized by SOM_COLORCODE.']); + end +elseif vis_valuetype(initRGB,{'nx3rgb',[munits 3]},'all'), + ; +else + error(['The initial color code must be a string '... + 'or an Mx3 matrix of RGB triples.']); +end + +%%% Action %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% + +disp('Wait...'); +[c,p,err,ind]=kmeans_clusters(sM,C,5,0); % use 5 trials, verbose off + +% Store outputs to kmeans +kmeans{1}=c; +kmeans{2}=p; +kmeans{3}=err; +kmeans{4}=ind; + +%%% Build output +color=som_clustercolor(sM,cat(2,p{:}),initRGB); +[tmp,best]=min(ind); + +switch contrast +case 'flat' + ; +case 'enhanced' + warning off; + ncolor=maxnorm(color); + ncolor(~isfinite(ncolor))=color(~isfinite(ncolor)); + color=ncolor; + warning on; +end + +%%% Subfunctions %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% +function X=maxnorm(x) +% normalize columns of x between [0,1] + +x=x-repmat(min(x),[size(x,1) 1 1]); +X=x./repmat(max(x),[size(x,1) 1 1]);