function options = svmlopt(varargin)% SVMLOPT - Generate/alter options structure for SVM light% %   OPTIONS = SVMLOPT('PARAM1',VALUE1,'PARAM2',VALUE2,...) creates an%   optimization options structure OPTIONS in which the named parameters%   have the specified values.  Any unspecified parameters are set to []%   (parameters with value [] indicate to use the default value for that%   parameter when OPTIONS is passed to SVM light. It is sufficient to type%   only the leading characters that uniquely identify the parameter.  Case%   is ignored for parameter names.%   OPTIONS = SVMLOPT(OLDOPTS,'PARAM1',VALUE1,...) creates a copy of OLDOPTS %   with the named parameters altered with the specified values.%   OPTIONS = SVMLOPT(OLDOPTS,NEWOPTS) combines an existing options structure%   OLDOPTS with a new options structure NEWOPTS.  Any parameters in NEWOPTS%   with non-empty values overwrite the corresponding old parameters in %   OLDOPTS. %   OPTIONS = SVMLOPT (with no input arguments) creates an options structure%   OPTIONS where all the fields are set to [].%%   The correspondence of the SVM light options to the field in the%   OPTIONS structure is as follows:%   Field          SVM light  Range, description%   'Verbosity'      -v       {0 .. 3}, default value 1%                             Verbosity level%   'Regression'     -z       {0, 1}, default value 0%                             Switch between regression [1] and%                             classification [0]%   'C'              -c       (0, Inf), default value (avg. x*x)^-1%                             Trade-off between error and margin%   'TubeWidth'      -w       (0, Inf), default value 0.1%                             Epsilon width of tube for regression%   'CostFactor'     -j       (0, Inf), default value 1%                             Cost-Factor by which training errors on%                             positive examples outweight errors on%                             negative examples%   'Biased'         -b       {0, 1}, default value 1%                             Use biased hyperplane x*w+b0 [1] instead of%                             unbiased x*w0 [0]%   'RemoveIncons'   -i       {0, 1}, default value 0%                             Remove inconsistent training examples and%                             retrain%   'ComputeLOO'     -x       {0, 1}, default value 0%                             Compute leave-one-out estimates [1]%   'XialphaRho'     -o       )0, 2), default value 1.0%                             Value of rho for XiAlpha-estimator and for%                             pruning leave-one-out computation%   'XialphaDepth'   -k       {0..100}, default value 0%                             Search depth for extended XiAlpha-estimator %   'TransPosFrac'   -p       (0..1), default value ratio of%                             positive and negative examples in the%                             training data. Fraction of unlabeled%                             examples to be classified into the positive%                             class%   'Kernel'         -t       {0..4}, default value 1%                             Type of kernel function:%                             0: linear%                             1: polynomial (s a*b+c)^d%                             2: radial basis function exp(-gamma ||a-b||^2)%                             3: sigmoid tanh(s a*b + c)%                             4: user defined kernel from kernel.h%   'KernelParam'    -d, -g, -s, -r, -u%                             Depending on the kernel, this vector%                             contains [d] for polynomial kernel, [gamma]%                             for RBF, [s, c] for tanh kernel, string for%                             user-defined kernel%   'MaximumQP'      -q       {2..}, default value 10%                             Maximum size of QP-subproblems%   'NewVariables'   -n       {2..}, default value is the value chosen%                             for 'MaximumQP'. Number of new variables%                             entering the working set in each%                             iteration. Use smaller values to prevent%                             zig-zagging%   'CacheSize'      -m       (5..Inf), default value 40.%                             Size of cache for kernel evaluations in MB%   'EpsTermin'      -e       (0..Inf), default value 0.001%                             Allow that error for termination criterion%                             [y [w*x+b] - 1] < eps%   'ShrinkIter'     -h       {5..Inf}, default value 100.%                             Number of iterations a variable needs to be%                             optimal before considered for shrinking%   'ShrinkCheck'    -f       {0, 1}, default value 1%                             Do final optimality check for variables%                             removed by shrinking. Although this test is%                             usually positive, there is no guarantee%                             that the optimum was found if the test is%                             omitted.%   'TransLabelFile' -l       String. File to write predicted labels of%                             unlabeled examples into after transductive%                             learning.%   'AlphaFile'      -a       String. Write all alphas to this file after%                             learning (in the same order as in the%                             training set).%%   See also SVML,SVM_LEARN,SVM_CLASSIFY%% % Copyright (c) by Anton Schwaighofer (2001)% $Revision: 1.7 $ $Date: 2002/05/30 10:33:28 $% mailto:anton.schwaighofer@gmx.net% % This program is released unter the GNU General Public License.% options = struct('ExecPath', [], ...                 'Verbosity', [], ...                 'Regression', [], ...                 'C', [], ...                 'TubeWidth', [], ...                 'CostFactor', [], ...                 'Biased', [], ...                 'RemoveIncons', [], ...                 'ComputeLOO', [], ...                 'XialphaRho', [], ...                 'XialphaDepth', [], ...                 'TransPosFrac', [], ...                 'Kernel', [], ...                 'KernelParam', [], ...                 'MaximumQP', [], ...                 'NewVariables', [], ...                 'CacheSize', [], ...                 'EpsTermin', [], ...                 'ShrinkIter', [], ...                 'ShrinkCheck', [], ...                 'TransLabelFile', [], ...                 'AlphaFile', []);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 {'Biased', 'ComputeLOO', 'ShrinkCheck'}    if isFloat,      if all(value~=[0 1]);        valid = 0;        errmsg = sprintf('Invalid value for %s parameter: Must be either 0 or 1', field);      end    end  case 'XialphaRho'    if ~isFloat | (value<=0) | (value>2),      valid = 0;      errmsg = sprintf('Invalid value for %s parameter: Must be scalar in the range (0, 2]', field);    end  case {'ExecPath', 'TransLabelFile', 'AlphaFile'}    if ~isString,      valid = 0;      errmsg = sprintf('Invalid value for %s parameter: Must be a string', field);    end  case 'RemoveIncons'    requireInt = 1;    range = [0 3];    % does not comply to the SVMlight help text, but is mentioned in the code  case 'Verbosity'    requireInt = 1;    range = [0 3];  case 'Regression'    requireInt = 1;    range = [0 1];  case {'C', 'CostFactor', 'EpsTermin', 'TubeWidth'}    range = [0 Inf];  case 'Kernel'    requireInt = 1;    range = [0 5];  case 'KernelParam'    valid = 1;  case 'XialphaDepth'    requireInt = 1;    range = [0 100];  case 'TransPosFrac'    range = [0 1];  case 'MaximumQP'    requireInt = 1;    range = [2, Inf];  case 'NewVariables'    requireInt = 1;    range = [2, Inf];  case 'CacheSize'    requireInt = 1;    range = [5, Inf];  case 'ShrinkIter'    requireInt = 1;    range = [5, Inf];  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