function options = ml_options(varargin)% ML_OPTIONS - Generate/alter options structure for training classifiers% ----------------------------------------------------------------------------------------%%   options = ml_options('PARAM1',VALUE1,'PARAM2',VALUE2,...) %%   Creates an options structure "options" in which the named parameters%   have the specified values.  Any unspecified parameters are set to%   default values specified below.%   options = ml_options (with no input arguments) creates an options structure%   "options" where all the fields are set to default values specified below.%%   Example: %          options=ml_options('Kernel','rbf','KernelParam',0.5,'NN',6);%%   "options" structure is as follows:%%            Field Name:  Description                                         : default % -------------------------------------------------------------------------------------%              'Kernel':  'linear' | 'rbf' | 'poly'                           : 'linear'%         'KernelParam':  --    | sigma | degree                              :  1 %                  'NN':  number of nearest neighbor                          :  6%'GraphDistanceFuncion':  distance function for graph: 'euclidean' | 'cosine' : 'euclidean' %        'GraphWeights':  'binary' | 'distance' | 'heat'                      : 'binary'%    'GraphWeightParam':  e.g For heat kernel, width to use                   :  1 %      'GraphNormalize':  Use normalized Graph laplacian (1) or not (0)       :  1%          'ClassEdges':  Disconnect Edges across classes:yes(1) no (0)       :  0%             'gamma_A':  RKHS norm regularization parameter (Ambient)        :  1 %             'gamma_I':  Manifold regularization parameter  (Intrinsic)      :  1    % -------------------------------------------------------------------------------------%% Acknowledgement: Adapted from Anton Schwaighofer's software:%               http://www.cis.tugraz.at/igi/aschwaig/software.html%% Author: Vikas Sindhwani (vikass@cs.uchicago.edu)% June 2004% ----------------------------------------------------------------------------------------%% options default valuesoptions = struct('Kernel','linear', ...                 'KernelParam',1, ...                 'NN',6,...                 'GraphDistanceFunction','euclidean',...                  'GraphWeights', 'binary', ...                 'GraphWeightParam',1, ...                 'GraphNormalize',1, ...                 'ClassEdges',0,...                 'gamma_A',1.0,...                  'gamma_I',1.0);   numberargs = nargin;Names = fieldnames(options);[m,n] = size(Names);names = lower(Names);i = 1;while i <= numberargs  arg = varargin{i};  if isstr(arg)    break;  end  if ~isempty(arg)    if ~isa(arg,'struct')      error(sprintf('Expected argument %d to be a string parameter name or an options structure.', i));    end    for j = 1:m      if any(strcmp(fieldnames(arg),Names{j,:}))        val = getfield(arg, Names{j,:});      else        val = [];      end      if ~isempty(val)        [valid, errmsg] = checkfield(Names{j,:},val);        if valid          options = setfield(options, Names{j,:},val);        else          error(errmsg);        end      end    end  end  i = i + 1;end% A finite state machine to parse name-value pairs.if rem(numberargs-i+1,2) ~= 0  error('Arguments must occur in name-value pairs.');endexpectval = 0;while i <= numberargs  arg = varargin{i};  if ~expectval    if ~isstr(arg)      error(sprintf('Expected argument %d to be a string parameter name.', i));    end    lowArg = lower(arg);    j = strmatch(lowArg,names);    if isempty(j)      error(sprintf('Unrecognized parameter name ''%s''.', arg));    elseif length(j) > 1       % Check for any exact matches (in case any names are subsets of others)      k = strmatch(lowArg,names,'exact');      if length(k) == 1        j = k;      else        msg = sprintf('Ambiguous parameter name ''%s'' ', arg);        msg = [msg '(' Names{j(1),:}];        for k = j(2:length(j))'          msg = [msg ', ' Names{k,:}];        end        msg = sprintf('%s).', msg);        error(msg);      end    end    expectval = 1;  else               [valid, errmsg] = checkfield(Names{j,:}, arg);    if valid      options = setfield(options, Names{j,:}, arg);    else      error(errmsg);    end    expectval = 0;  end  i = i + 1;end  function [valid, errmsg] = checkfield(field,value)% CHECKFIELD Check validity of structure field contents.%   [VALID, MSG] = CHECKFIELD('field',V) checks the contents of the specified%   value V to be valid for the field 'field'.%valid = 1;errmsg = '';if isempty(value)  returnendisFloat = length(value==1) & isa(value, 'double');isPositive = isFloat & (value>=0);isString = isa(value, 'char');range = [];requireInt = 0;switch field  case 'NN'    requireInt = 1;    range=[1 Inf]; case 'GraphNormalize'     requireInt = 1;     range=[0 1];   case 'ClassEdges'     requireInt = 1;     range=[0 1];    case {'Kernel', 'GraphWeights', 'GraphDistanceFunction'}    if ~isString,      valid = 0;      errmsg = sprintf('Invalid value for %s parameter: Must be a string', field);    end  case {'gamma_A', 'gamma_I','GraphWeightParam'}    range = [0 Inf];  case 'KernelParam'    valid = 1;   otherwise    valid = 0;    error('Unknown field name for Options structure.')endif ~isempty(range),  if (value<range(1)) | (value>range(2)),    valid = 0;    errmsg = sprintf('Invalid value for %s parameter: Must be scalar in the range [%g..%g]', ...                     field, range(1), range(2));  endendif requireInt & ((value-round(value))~=0),  valid = 0;  errmsg = sprintf('Invalid value for %s parameter: Must be integer', ...                   field);end