wolffd@0: function sMap = som_randinit(D, varargin)
wolffd@0: 
wolffd@0: %SOM_RANDINIT Initialize a Self-Organizing Map with random values.
wolffd@0: %
wolffd@0: % sMap = som_randinit(D, [[argID,] value, ...])
wolffd@0: %
wolffd@0: %  sMap = som_randinit(D);
wolffd@0: %  sMap = som_randinit(D,sMap);
wolffd@0: %  sMap = som_randinit(D,'munits',100,'hexa');
wolffd@0: % 
wolffd@0: %  Input and output arguments ([]'s are optional): 
wolffd@0: %    D                 The training data.
wolffd@0: %             (struct) data struct
wolffd@0: %             (matrix) data matrix, size dlen x dim
wolffd@0: %   [argID,   (string) Parameters affecting the map topology are given 
wolffd@0: %    value]   (varies) as argument ID - argument value pairs, listed below.
wolffd@0: %
wolffd@0: %   sMap      (struct) map struct
wolffd@0: %
wolffd@0: % Here are the valid argument IDs and corresponding values. The values 
wolffd@0: % which are unambiguous (marked with '*') can be given without the
wolffd@0: % preceeding argID.
wolffd@0: %  'munits'       (scalar) number of map units
wolffd@0: %  'msize'        (vector) map size
wolffd@0: %  'lattice'     *(string) map lattice: 'hexa' or 'rect'
wolffd@0: %  'shape'       *(string) map shape: 'sheet', 'cyl' or 'toroid'
wolffd@0: %  'topol'       *(struct) topology struct
wolffd@0: %  'som_topol','sTopol'    = 'topol'
wolffd@0: %  'map'         *(struct) map struct
wolffd@0: %  'som_map','sMap'        = 'map'
wolffd@0: %
wolffd@0: % For more help, try 'type som_randinit' or check out online documentation.
wolffd@0: % See also SOM_MAP_STRUCT, SOM_LININIT, SOM_MAKE.
wolffd@0: 
wolffd@0: %%%%%%%%%%%%% DETAILED DESCRIPTION %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
wolffd@0: %
wolffd@0: % som_randinit
wolffd@0: %
wolffd@0: % PURPOSE
wolffd@0: %
wolffd@0: % Initializes a SOM with random values.
wolffd@0: %
wolffd@0: % SYNTAX
wolffd@0: %
wolffd@0: %  sMap = som_randinit(D)
wolffd@0: %  sMap = som_randinit(D,sMap);
wolffd@0: %  sMap = som_randinit(D,'munits',100,'hexa');
wolffd@0: %
wolffd@0: % DESCRIPTION
wolffd@0: %
wolffd@0: % Initializes a SOM with random values. If necessary, a map struct
wolffd@0: % is created first. For each component (xi), the values are uniformly
wolffd@0: % distributed in the range of [min(xi) max(xi)]. 
wolffd@0: %
wolffd@0: % REQUIRED INPUT ARGUMENTS
wolffd@0: %
wolffd@0: %  D                 The training data.
wolffd@0: %           (struct) Data struct. If this is given, its '.comp_names' and 
wolffd@0: %                    '.comp_norm' fields are copied to the map struct.
wolffd@0: %           (matrix) data matrix, size dlen x dim
wolffd@0: %  
wolffd@0: % OPTIONAL INPUT ARGUMENTS 
wolffd@0: %
wolffd@0: %  argID (string) Argument identifier string (see below).
wolffd@0: %  value (varies) Value for the argument (see below).
wolffd@0: %
wolffd@0: %  The optional arguments can be given as 'argID',value -pairs. If an
wolffd@0: %  argument is given value multiple times, the last one is used. 
wolffd@0: %
wolffd@0: %  Here are the valid argument IDs and corresponding values. The values 
wolffd@0: %  which are unambiguous (marked with '*') can be given without the 
wolffd@0: %  preceeding argID.
wolffd@0: %  'dlen'         (scalar) length of the training data
wolffd@0: %  'data'         (matrix) the training data
wolffd@0: %                *(struct) the training data
wolffd@0: %  'munits'       (scalar) number of map units
wolffd@0: %  'msize'        (vector) map size
wolffd@0: %  'lattice'     *(string) map lattice: 'hexa' or 'rect'
wolffd@0: %  'shape'       *(string) map shape: 'sheet', 'cyl' or 'toroid'
wolffd@0: %  'topol'       *(struct) topology struct
wolffd@0: %  'som_topol','sTopol'    = 'topol'
wolffd@0: %  'map'         *(struct) map struct
wolffd@0: %  'som_map','sMap'        = 'map'
wolffd@0: %
wolffd@0: % OUTPUT ARGUMENTS
wolffd@0: % 
wolffd@0: %  sMap     (struct) The initialized map struct.
wolffd@0: %
wolffd@0: % EXAMPLES
wolffd@0: %
wolffd@0: %  sMap = som_randinit(D);
wolffd@0: %  sMap = som_randinit(D,sMap);
wolffd@0: %  sMap = som_randinit(D,sTopol);
wolffd@0: %  sMap = som_randinit(D,'msize',[10 10]);
wolffd@0: %  sMap = som_randinit(D,'munits',100,'hexa');
wolffd@0: %
wolffd@0: % SEE ALSO
wolffd@0: % 
wolffd@0: %  som_map_struct   Create a map struct.
wolffd@0: %  som_lininit      Initialize a map using linear initialization algorithm.
wolffd@0: %  som_make         Initialize and train self-organizing map.
wolffd@0: 
wolffd@0: % Copyright (c) 1997-2000 by the SOM toolbox programming team.
wolffd@0: % http://www.cis.hut.fi/projects/somtoolbox/
wolffd@0: 
wolffd@0: % Version 1.0beta ecco 100997
wolffd@0: % Version 2.0beta juuso 101199
wolffd@0: 
wolffd@0: %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
wolffd@0: %% check arguments
wolffd@0: 
wolffd@0: % data
wolffd@0: if isstruct(D), 
wolffd@0:   data_name = D.name; 
wolffd@0:   comp_names = D.comp_names; 
wolffd@0:   comp_norm = D.comp_norm; 
wolffd@0:   D = D.data;
wolffd@0:   struct_mode = 1; 
wolffd@0: else 
wolffd@0:   data_name = inputname(1); 
wolffd@0:   struct_mode = 0; 
wolffd@0: end
wolffd@0: [dlen dim] = size(D);
wolffd@0: 
wolffd@0: % varargin
wolffd@0: sMap = [];
wolffd@0: sTopol = som_topol_struct; 
wolffd@0: sTopol.msize = 0; 
wolffd@0: munits = NaN;
wolffd@0: i=1; 
wolffd@0: while i<=length(varargin), 
wolffd@0:   argok = 1; 
wolffd@0:   if ischar(varargin{i}), 
wolffd@0:     switch varargin{i}, 
wolffd@0:      case 'munits',     i=i+1; munits = varargin{i}; sTopol.msize = 0;
wolffd@0:      case 'msize',      i=i+1; sTopol.msize = varargin{i};
wolffd@0:                                munits = prod(sTopol.msize); 
wolffd@0:      case 'lattice',    i=i+1; sTopol.lattice = varargin{i}; 
wolffd@0:      case 'shape',      i=i+1; sTopol.shape = varargin{i}; 
wolffd@0:      case {'som_topol','sTopol','topol'}, i=i+1; sTopol = varargin{i}; 
wolffd@0:      case {'som_map','sMap','map'}, i=i+1; sMap = varargin{i}; sTopol = sMap.topol;
wolffd@0:      case {'hexa','rect'},          sTopol.lattice = varargin{i}; 
wolffd@0:      case {'sheet','cyl','toroid'}, sTopol.shape = varargin{i};
wolffd@0:      otherwise argok=0; 
wolffd@0:     end
wolffd@0:   elseif isstruct(varargin{i}) & isfield(varargin{i},'type'), 
wolffd@0:     switch varargin{i}.type, 
wolffd@0:      case 'som_topol',
wolffd@0:       sTopol = varargin{i}; 
wolffd@0:      case 'som_map', 
wolffd@0:       sMap = varargin{i};
wolffd@0:       sTopol = sMap.topol;
wolffd@0:      otherwise argok=0; 
wolffd@0:     end
wolffd@0:   else
wolffd@0:     argok = 0; 
wolffd@0:   end
wolffd@0:   if ~argok, 
wolffd@0:     disp(['(som_topol_struct) Ignoring invalid argument #' num2str(i)]); 
wolffd@0:   end
wolffd@0:   i = i+1; 
wolffd@0: end
wolffd@0: 
wolffd@0: if ~isempty(sMap), 
wolffd@0:   [munits dim2] = size(sMap.codebook);
wolffd@0:   if dim2 ~= dim, error('Map and data must have the same dimension.'); end
wolffd@0: end
wolffd@0: 
wolffd@0: %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
wolffd@0: %% create map
wolffd@0: 
wolffd@0: % map struct
wolffd@0: if ~isempty(sMap), 
wolffd@0:   sMap = som_set(sMap,'topol',sTopol);
wolffd@0: else  
wolffd@0:   if ~prod(sTopol.msize), 
wolffd@0:     if isnan(munits), 
wolffd@0:       sTopol = som_topol_struct('data',D,sTopol);
wolffd@0:     else
wolffd@0:       sTopol = som_topol_struct('data',D,'munits',munits,sTopol);
wolffd@0:     end
wolffd@0:   end  
wolffd@0:   sMap = som_map_struct(dim, sTopol); 
wolffd@0: end
wolffd@0: 
wolffd@0: if struct_mode, 
wolffd@0:   sMap = som_set(sMap,'comp_names',comp_names,'comp_norm',comp_norm);
wolffd@0: end
wolffd@0: 
wolffd@0: %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
wolffd@0: %% initialization
wolffd@0: 
wolffd@0: % train struct
wolffd@0: sTrain = som_train_struct('algorithm','randinit');
wolffd@0: sTrain = som_set(sTrain,'data_name',data_name);
wolffd@0: 
wolffd@0: munits = prod(sMap.topol.msize);
wolffd@0: sMap.codebook = rand([munits dim]); 
wolffd@0: 
wolffd@0: % set interval of each component to correct value
wolffd@0: for i = 1:dim,
wolffd@0:   inds = find(~isnan(D(:,i)) & ~isinf(D(:,i))); 
wolffd@0:   if isempty(inds), mi = 0; ma = 1; 
wolffd@0:   else ma = max(D(inds,i)); mi = min(D(inds,i));  
wolffd@0:   end
wolffd@0:   sMap.codebook(:,i) = (ma - mi) * sMap.codebook(:,i) + mi; 
wolffd@0: end
wolffd@0: 
wolffd@0: % training struct
wolffd@0: sTrain = som_set(sTrain,'time',datestr(now,0));
wolffd@0: sMap.trainhist = sTrain;
wolffd@0: 
wolffd@0: return;
wolffd@0: 
wolffd@0: %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%