getN

GETN  Returns the number of elements of a given set type.
   N = OBJ.GETN(SET_TYPE)
   N = OBJ.GETN(SET_TYPE, NAME)
   N = OBJ.GETN(SET_TYPE, NAME, IDX_LIST)

   Returns either the total number of elements of a given set type
   (e.g. variable, constraint, etc.) or the number corresponding to a
   specified named block, or indexed named set.

   Examples:
       N = obj.getN('var')      : total number of variables
       N = obj.getN('lin')      : total number of linear constraints
       N = obj.getN('var', name)    : # of variables in named set
       N = obj.getN('lin', name)    : # of linear constraints in named set
       N = obj.getN('var', name, idx) : # of variables in indexed named set

   See also OPT_MODEL.

0001 function N = getN(obj, set_type, name, idx)
0002 %GETN  Returns the number of elements of a given set type.
0003 %   N = OBJ.GETN(SET_TYPE)
0004 %   N = OBJ.GETN(SET_TYPE, NAME)
0005 %   N = OBJ.GETN(SET_TYPE, NAME, IDX_LIST)
0006 %
0007 %   Returns either the total number of elements of a given set type
0008 %   (e.g. variable, constraint, etc.) or the number corresponding to a
0009 %   specified named block, or indexed named set.
0010 %
0011 %   Examples:
0012 %       N = obj.getN('var')      : total number of variables
0013 %       N = obj.getN('lin')      : total number of linear constraints
0014 %       N = obj.getN('var', name)    : # of variables in named set
0015 %       N = obj.getN('lin', name)    : # of linear constraints in named set
0016 %       N = obj.getN('var', name, idx) : # of variables in indexed named set
0017 %
0018 %   See also OPT_MODEL.
0019 
0020 %   MP-Opt-Model
0021 %   Copyright (c) 2008-2020, Power Systems Engineering Research Center (PSERC)
0022 %   by Ray Zimmerman, PSERC Cornell
0023 %
0024 %   This file is part of MP-Opt-Model.
0025 %   Covered by the 3-clause BSD License (see LICENSE file for details).
0026 %   See https://github.com/MATPOWER/mp-opt-model for more info.
0027 
0028 if nargin < 3
0029     N = obj.(set_type).N;
0030 else
0031     if isfield(obj.(set_type).idx.N, name)
0032         if nargin < 4 || isempty(idx)
0033             N = obj.(set_type).idx.N.(name);
0034         else
0035             % s1 = substruct('.', name, '()', idx);
0036             sn = struct('type', {'.', '()'}, 'subs', {name, idx});  %% num array field
0037             N = subsref(obj.(set_type).idx.N, sn);
0038         end
0039     else
0040         N = 0;
0041     end
0042 end