milpsubsref.m

optimization toolbox

function varargout = milpsubsref(varargin)
%MILPSUBSREF

% Author Johan L鰂berg
% $Id: milpsubsref.m,v 1.3 2006/04/27 13:03:15 joloef Exp $

switch class(varargin{1})
    case 'double'
        varargin{1} = double(varargin{1});
        varargin{2}.subs{1} = double(varargin{2}.subs{1});
        varargout{1} = subsref(varargin{:});

    case 'sdpvar'
        switch length(varargin{2}.subs)
            case 1                
                index = varargin{2}.subs{1};
                if length(index) > 1
                    y = [];
                    for i = 1:length(index)
                        varargin{2}.subs{1} = index(i);
                        y = [y;yalmip('addextendedvariable',mfilename,varargin{:})];
                    end
                    % Figure out dims of variable
                    X = randn(size(varargin{1}));
                    varargin{2}.subs{1} = ones(size(index));
                    X = subsref(X,varargin{2});
                    y = reshape(y,size(X,1),size(X,2));
                    varargout{1} = y;
                else
                    varargout{1} = yalmip('addextendedvariable',mfilename,varargin{:});
                end
            case 2
                index1 = varargin{2}.subs{1};
                index2 = varargin{2}.subs{2};
                y = [];
                for i = 1:length(index1)
                    temp = [];
                    for j = 1:length(index2)
                        varargin{2}.subs{1} = index1(i);
                        varargin{2}.subs{2} = index2(j);
                        temp = [temp yalmip('addextendedvariable',mfilename,varargin{:})];
                    end
                    y = [y;temp];
                end
                % Figure out dims of variable
                X = randn(size(varargin{1}));
                varargin{2}.subs{1} = ones(size(index1));
                varargin{2}.subs{2} = ones(size(index2));
                X = subsref(X,varargin{2});
                y = reshape(y,size(X,1),size(X,2));
                varargout{1} = y;

                
            otherwise
                error('Only 1D and 2D variable subsref implemented');
        end

    case 'char'
        switch varargin{1}
            case {'graph','milp'}
                X = varargin{3};
                Y = varargin{2};
                if length(varargin{4}.subs) == 1
                    i = varargin{4}.subs{1};
                    M = length(X);
                    m = 1;
                    F = set(integer(i)); % just to be sure
                    d = binvar(length(X),1);
                    [Mx,mx]=derivebounds(X);
                    for j = m:M
                        di = d(j);
%                        F = F + set(mx*(1-di) <= Y-X(j) <= Mx*(1-di));
                        F = F + set(-(max(Mx)-min(mx))*(1-di) <= Y-X(j) <= (max(Mx)-min(mx))*(1-di));                        
                        F = F + set(-(1+M-m)*(1-di) <= i-j <= (1+M-m)*(1-di));
                    end
                    F = F + set(sum(d)==1);
                else
                    i1 = varargin{4}.subs{1};
                    i2 = varargin{4}.subs{2};
                    M1 = size(X,1);
                    M2 = size(X,2);
                    m1 = 1;
                    m2 = 1;
                    if isa(i1,'sdpvar')
                        F = set(integer(i1)); % just to be sure
                    end
                    if isa(i2,'sdpvar')
                        F = set(integer(i2)); % just to be sure
                    end
                    d = binvar(size(X,1),size(X,2),'full');
                    [Mx,mx]=derivebounds(X);
                    for i = m1:M1
                        for j = m2:M2
                            di = d(i,j);
                            F = F + set(-(max(Mx)-min(mx))*(1-di) <= Y-X(i,j) <= (max(Mx)-min(mx))*(1-di));
                            if isa(i1,'sdpvar')
                                F = F + set(-(1+M1-m1)*(1-di) <= i1-i <= (1+M1-m1)*(1-di));
                            end
                            if isa(i2,'sdpvar')
                                F = F + set(-(1+M2-m2)*(1-di) <= i2-j <= (1+M2-m2)*(1-di));
                            end
                        end
                    end
                    F = F + set(sum(sum(d))==1);
                    
                end
                varargout{1} = F;
                varargout{2} = struct('convexity','none','monotonicity','none','definiteness','none');
                varargout{3} = [X(:);i(:)];

            otherwise
                error('SDPVAR/ABS called with CHAR argument?');
        end
    otherwise
        error('Strange type on first argument in SDPVAR/ABS');
end