1 | function Z = replace(X,Y,W) |
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2 | %REPLACE Substitutes variables |
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3 | % |
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4 | %Z = REPLACE(Y,X,W) Replaces any occurence of the SDPVAR object Y |
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5 | % in the SDPVAR object X with the double W |
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6 | % |
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7 | % Example |
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8 | % x = sdpvar(1,1); |
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9 | % t = sdpvar(1,1); |
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10 | % Y = [1+t;1+x+t]; |
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11 | % Y = replace(Y,x,2) generates Y=[1+t;3+t] |
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12 | |
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13 | % Author Johan Löfberg |
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14 | % $Id: replace.m,v 1.15 2006/08/24 08:35:24 joloef Exp $ |
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15 | |
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16 | if ~isa(X,'sdpvar') |
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17 | Z = X; |
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18 | return |
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19 | end |
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20 | if ~isa(Y,'sdpvar') |
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21 | error('Second arguments must be an sdpvar object') |
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22 | end |
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23 | |
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24 | if ~is(Y,'linear') |
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25 | error('Second arguments must be linear') |
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26 | end |
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27 | |
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28 | if prod(size(W)) == 1 |
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29 | W = repmat(W,size(Y)); |
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30 | end |
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31 | |
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32 | if ~isequal(size(Y),size(W)) |
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33 | error('Both arguments must have same size') |
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34 | end |
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35 | |
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36 | if isa(W,'sdpvar') |
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37 | % This is tricky... |
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38 | Z = variable_replace(X,Y,W); |
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39 | return |
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40 | end |
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41 | |
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42 | if ~isa(W,'double') |
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43 | error('Third arguments must be a double') |
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44 | end |
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45 | |
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46 | % Replace with NaN destroys everything, assume it should be cleared |
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47 | W(isnan(W)) = 0; |
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48 | |
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49 | y_lmi_variables = Y.lmi_variables; |
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50 | b = W(:)-Y.basis(:,1); |
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51 | A = Y.basis(:,2:end); |
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52 | feas_var = A\b; |
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53 | if norm(A*feas_var-b)>sqrt(eps) |
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54 | error('Inconsistent assignment') |
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55 | end |
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56 | |
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57 | x_lmi_variables = X.lmi_variables; |
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58 | n = X.dim(1); |
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59 | m = X.dim(2); |
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60 | |
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61 | [monomtable,variabletype] = yalmip('monomtable'); |
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62 | if all(variabletype(x_lmi_variables)==0) % is(X,'linear') |
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63 | Z = X.basis(:,1); |
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64 | for i = 1:length(x_lmi_variables) |
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65 | j = find(x_lmi_variables(i) == y_lmi_variables); |
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66 | if isempty(j) |
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67 | Z = Z + recover(x_lmi_variables(i))*X.basis(:,i+1); |
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68 | else |
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69 | Z = Z + feas_var(j)*X.basis(:,i+1); |
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70 | end |
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71 | end |
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72 | else |
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73 | replaced_vars = depends(Y); |
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74 | % used_variables = getvariables(X); |
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75 | used_variables = x_lmi_variables; |
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76 | % monomtable = yalmip('monomtable'); |
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77 | local_monom = monomtable(used_variables,replaced_vars); |
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78 | W = W(:)'; |
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79 | gain = zeros(length(used_variables),1); |
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80 | for i = 1:length(used_variables) |
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81 | % F**N 6.5 0^sparse(0) and 0^0 differ |
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82 | gain(i) = prod(W.^full(local_monom(i,:))); |
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83 | end |
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84 | |
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85 | local_monoms_left = monomtable(used_variables,:); |
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86 | local_monoms_left(:,replaced_vars) = 0; |
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87 | used_left = find(sum(local_monoms_left,1)); |
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88 | base = recovermonoms(local_monoms_left(:,used_left),recover(used_left)); |
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89 | base = base.*gain(:); |
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90 | Z = X.basis(:,1); |
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91 | Z = Z + X.basis(:,2:end)*base; |
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92 | end |
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93 | |
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94 | Xvariables = getvariables(Z); |
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95 | extvar = yalmip('extvariables'); |
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96 | Xext = find(ismember(Xvariables,extvar)); |
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97 | if ~isempty(Xext) |
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98 | %We must dig down in extended operators to see if they use the replaced |
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99 | %set of variables |
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100 | for i = 1:length(Xext) |
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101 | extstruct = yalmip('extstruct',Xvariables(Xext(i))); |
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102 | anychanged = 0; |
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103 | for j = 1:length(extstruct.arg) |
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104 | if isa(extstruct.arg{j},'sdpvar') |
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105 | XinY = find(ismembc(getvariables(extstruct.arg{j}),y_lmi_variables)); |
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106 | if ~isempty(XinY) |
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107 | anychanged = 1; |
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108 | extstruct.arg{j} = replace(extstruct.arg{j},Y,W); |
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109 | else |
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110 | end |
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111 | end |
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112 | end |
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113 | if anychanged |
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114 | Zi = yalmip('addextendedvariable',extstruct.fcn,extstruct.arg{:}); |
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115 | Xvariables(Xext(i)) = getvariables(Zi); |
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116 | end |
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117 | end |
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118 | % And now recover this sucker |
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119 | Z = struct(Z); |
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120 | Z.lmi_variables = Xvariables; |
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121 | % Fucked up order (lmi_variables should be sorted) |
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122 | if any(diff(Z.lmi_variables)<0) |
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123 | [i,j]=sort(Z.lmi_variables); |
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124 | Z.basis = [Z.basis(:,1) Z.basis(:,j+1)]; |
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125 | Z.lmi_variables = Z.lmi_variables(j); |
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126 | end |
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127 | Z = sdpvar(Z.dim(1),Z.dim(2),[],Z.lmi_variables,Z.basis); |
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128 | end |
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129 | |
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130 | |
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131 | if isa(Z,'sdpvar') |
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132 | Z.dim(1) = n; |
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133 | Z.dim(2) = m; |
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134 | Z.typeflag = X.typeflag; |
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135 | % Reset info about conic terms |
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136 | Z.conicinfo = [0 0]; |
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137 | else |
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138 | Z = reshape(full(Z),n,m); |
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139 | end |
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140 | |
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148 | |
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