24 lines
943 B
Mathematica
24 lines
943 B
Mathematica
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function varargout = invpos(varargin)
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% INVPOS Returns model of 1./x
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switch class(varargin{1})
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case 'double' % What is the numerical value of this argument (needed for displays etc)
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varargout{1} = 1./varargin{1};
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case 'sdpvar' % Overloaded operator for SDPVAR objects. Pass on args and save them.
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varargout{1} = InstantiateElementWise(mfilename,varargin{:});
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case 'char' % YALMIP sends 'model' when it wants the epigraph or hypograph
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if isequal(varargin{1},'graph')
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t = varargin{2}; % Second arg is the extended operator variable
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X = varargin{3}; % Third arg and above are the args user used when defining t.
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varargout{1} = (cone([2;X-t],X+t));
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varargout{2} = struct('convexity','convex','monotonicity','decreasing','definiteness','positive','model','graph');
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varargout{3} = X;
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else
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end
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otherwise
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end
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