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