58 lines
1.1 KiB
Mathematica
58 lines
1.1 KiB
Mathematica
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function X=sos(X,r)
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%SOS Declare sum-of-squares structure
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%
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% F = sos(p)
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%
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% Input
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% p : SDPVAR object
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% Output
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% F : Constraint
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%
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% Example:
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% Typical usage is
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%
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% F = sos(p)
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%
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% An experimental feature is to search for
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% low rank decompositions. To search for a
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% decomposition using at most 3 terms, use
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% a second argument
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%
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% F = sos(p,3)
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%
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% Note that his feature requires the solver LMIRANK.
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if nargin<2
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r = inf;
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end
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if any(isinf(getbase(X)))
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error('You have infinite elements in the polynomial');
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end
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if any(isnan(getbase(X)))
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error('You have NaN elements in the polynomial');
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end
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if ~is(X,'symmetric')
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% User supplied a vector
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X = reshape(X,prod(size(X)),1);
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Z = [];
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for i = 1:length(X)
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I.type = '()';
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I.subs = {[i]};
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x = subsref(X,I);
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if isnumeric(x)
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if x < 0
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error('You are trying to enforce a negative constant to be SOS!');
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end
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else
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Z = [Z,sos(x)];
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end
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end
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X = Z;
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else
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X.typeflag = 11;
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X.extra.sosid = yalmip('sosid');
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X.extra.rank = r;
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X = lmi(X);
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end
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