function Col = som_coloring(sM,ncol,chaingap,dw)% SOM_COLORING Make a SOM-based coloring for given data/map.%% Col = som_coloring(sM,[ncol],[chaingap],[dw])% %  Col = som_coloring(sM,5);%  som_show(sM,'color',Col); %% Input and output arguments ([]'s are optional):%  sM          (struct) map or data struct%              (matrix) data matrix%  [ncol]      (scalar) number of colors to use%  [chaingap]  (scalar) size of gap in the color circle (see below), %                       0.1 by default%  [dw]        (scalar) 1 = use input space distances to stretch%                           the color circle (default) %                       0 = don't use%%  Col         (matrix) color for each data/codebook vector%% This function trains a 1-dimensional SOM using the input data% (codebook of a SOM, or a set of data vectors). A color from the % color circle (see HSV function) is associated with each map unit, % and each data/codebook vector of the input data picks its color% from its BMU on the 1-dimensional SOM. %% If the chaingap argument == 0, the 1-dimensional map has a cylinder% (in effect, a ring) topology. Otherwise, the topology is rectangular% (in effect, a chain). %% The colors are mapped to the 1-dimensional SOM simply by picking colors% from the color circle. If chaingap>0, a slice of the color circle is% removed before map units pick their colors from it. This creates a% discontiuity in the coloring at the ends of the 1-dimensional SOM.%% If the dw argument == 0, the colors are picked from the color circle% equidistantly. If not, the distances between the prototype vectors% in the 1-dimensional SOM are taken into account.%% See also SOM_KMEANSCOLOR, SOM_KMEANSCOLOR2, SOM_FUZZYCOLOR.% Contributed to SOM Toolbox 2.0, December 21st, 2001 by Juha Vesanto % http://www.cis.hut.fi/projects/somtoolbox/             % Version 2.0beta juuso 211201%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%if isstruct(sM),   if strcmp(sM.type,'som_map'), ismap = 1; D = sM.codebook;   else ismap = 0; D = sM.data;   endelse ismap = 0; D = sM; endif nargin<2 | isempty(ncol) | isnan(ncol), ncol = min(64,size(D,1)); endif nargin<3 | isempty(chaingap) | isnan(chaingap), chaingap = 0.1; endif nargin<4 | isempty(dw) | isnan(dw), dw = 1; endif chaingap == 0, lattice = 'sheet'; else lattice = 'cyl'; endsMring = som_make(D,'msize',[1,ncol],lattice,'tracking',0);b = som_bmus(sMring,D);Colmap = hsv(ceil(ncol*(1+chaingap))); Colmap = Colmap(1:ncol,:);if dw, % take distances in input space into account  dist = sqrt(sum((sMring.codebook-sMring.codebook([2:end 1],:)).^2,2));    ind  = round([0; cumsum(dist)/sum(dist)]*(ncol-1)) + 1;  Colmap = Colmap(ind,:);end  Col = Colmap(b,:); return; %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% visualization  if ismap,     a = som_bmus(sM.codebook,sMring.codebook);     if chaingap==0, a(end+1) = a(1); end    som_show(sM,'color',Col);     som_show_add('traj',a)   else    i = find(sum(isnan(D),2)==0);     [P,V,me] = pcaproj(D(i,:),2);     Pr = pcaproj(sMring.codebook,V,me);    a = som_bmus(D(i,:),sMring.codebook); % Pr = P(a,:);    som_grid({'rect',[length(i) 1]},'line','none',...             'coord',P,'markercolor',Col(i,:));    hold on    if chaingap==0, Pr(end+1,:) = Pr(1,:); end    som_grid({'rect',[size(Pr,1) 1]},'linecolor','k',...             'linewidth',2,'markercolor','k','coord',Pr);  end