function unit_coord=som_vis_coords(lattice, msize)%SOM_VIS_COORDS Unit coordinates used in visualizations.% % Co = som_vis_coords(lattice, msize)%%  Co = som_vis_coords('hexa',[10 7])%  Co = som_vis_coords('rectU',[10 7])%%  Input and output arguments: %   lattice   (string) 'hexa', 'rect', 'hexaU' or 'rectU'%   msize     (vector) grid size in a 1x2 vector    %%   Co        (matrix) Mx2 matrix of unit coordinates, where %               M=prod(msize) for 'hexa' and 'rect', and %               M=(2*msize(1)-1)*(2*msize(2)-1) for 'hexaU' and 'rectU'%% This function calculates the coordinates of map units on a 'sheet'% shaped map with either 'hexa' or 'rect' lattice as used in the% visualizations. Note that this slightly different from the% coordinates provided by SOM_UNIT_COORDS function. %% 'rectU' and 'hexaU' gives the coordinates of both units and the% connections for u-matrix visualizations.%% For more help, try 'type som_vis_coords' or check out online documentation.% See also SOM_UNIT_COORDS, SOM_UMAT, SOM_CPLANE, SOM_GRID.%%%%%%%%% DETAILED DESCRIPTION %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% PURPOSE % % Returns coordinates of the map units for map visualization%% SYNTAX%%  Co = som_vis_coords(lattice, msize)%% DESCRIPTION%% This function calculates the coordinates of map units in 'hexa' and% 'rect' lattices in 'sheet' shaped map for visualization purposes. It% differs from SOM_UNIT_COORDS in the sense that hexagonal lattice is% calculated in a "wrong" way in order to get integer coordinates for% the units. Another difference is that it may be used to calculate% the coordinates of units _and_ the center points of the lines% connecting them (edges) by using 'hexaU' or 'rectU' for lattice. % This property may be used for drawing u-matrices.%% The unit number 1 is set to (ij) coordinates (1,1)+shift%                 2                            (2,1)+shift%%  ... columnwise% %             n-1th                        (n1-1,n2)+shift%             nth                            (n1,n2)+shift%% where grid size = [n1 n2] and shift is zero, except for % the even lines of 'hexa' lattice, for which it is +0.5.%% For 'rectU' and 'hexaU' the unit coordinates are the same and the% coordinates for connections are set according to these. In this case% the ordering of the coordinates is the following:%   let%     U  = som_umat(sMap); U=U(:); % make U a column vector%     Uc = som_vis_coords(sMap.topol.lattice, sMap.topol.msize); %   now the kth row of matrix Uc, i.e. Uc(k,:), contains the coordinates %   for value U(k). %% REQUIRED INPUT ARGUMENTS %%  lattice  (string) The local topology of the units: %                    'hexa', 'rect', 'hexaU' or 'rectU'%  msize    (vector) size 1x2, defining the map grid size. %                    Notice that only 2-dimensional grids%                    are allowed.%% OUTPUT ARGUMENTS% %  Co       (matrix) size Mx2, giving the coordinates for each unit.%                    M=prod(msize) for 'hexa' and 'rect', and %                    M=(2*msize(1)-1)*(2*msize(2)-1) for 'hexaU' and 'rectU'%% FEATURES% % Only 'sheet' shaped maps are considered. If coordinates for 'toroid'% or 'cyl' topologies are required, you must use SOM_UNIT_COORDS% instead.%% EXAMPLES%% Though this is mainly a subroutine for visualizations it may be% used, e.g., in the following manner:%% % This makes a hexagonal lattice, where the units are rectangular% % instead of hexagons.%    som_cplane('rect',som_vis_coords('hexa',[10 7]),'none');%% % Let's make a map and calculate a u-matrix: %    sM=som_make(data,'msize',[10 7],'lattice','hexa');%    u=som_umat(sM); u=u(:);% % Now, these produce equivalent results:%    som_cplane('hexaU',[10 7],u);%    som_cplane(vis_patch('hexa')/2,som_vis_coords('hexaU',[10 7]),u);%% SEE ALSO%% som_grid         Visualization of a SOM grid% som_cplane       Visualize a 2D component plane, u-matrix or color plane% som_barplane     Visualize the map prototype vectors as bar diagrams% som_plotplane    Visualize the map prototype vectors as line graphs% som_pieplane     Visualize the map prototype vectors as pie charts% som_unit_coords  Locations of units on the SOM grid% Copyright (c) 1999-2000 by the SOM toolbox programming team.% http://www.cis.hut.fi/projects/somtoolbox/             % Version 2.0beta Johan 201099 juuso 261199%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%if ~vis_valuetype(msize,{'1x2'}),  error('msize must be a 1x2 vector.')endif vis_valuetype(lattice,{'string'})  switch lattice  case {'hexa', 'rect'}    munits=prod(msize);    unit_coord(:,1)=reshape(repmat([1:msize(2)],msize(1),1),1,munits)';    unit_coord(:,2)=repmat([1:msize(1)]',msize(2),1);    if strcmp(lattice,'hexa')      % Move even rows by .5      d=rem(unit_coord(:,2),2) == 0;         unit_coord(d,1)=unit_coord(d,1)+.5;    end  case {'hexaU','rectU'}    msize=2*msize-1; munits=prod(msize);    unit_coord(:,1)=reshape(repmat([1:msize(2)],msize(1),1),1,munits)';    unit_coord(:,2)=repmat([1:msize(1)]',msize(2),1);    if strcmp(lattice,'hexaU')      d=rem(unit_coord(:,2),2) == 0;         unit_coord(d,1)=unit_coord(d,1)+.5;      d=rem(unit_coord(:,2)+1,4) == 0;       unit_coord(d,1)=unit_coord(d,1)+1;    end    unit_coord=unit_coord/2+.5;  otherwise    error([ 'Unknown lattice ''' lattice '''.']);  endelse  error('Lattice must be a string.');end