46 lines
1.1 KiB
Matlab
Executable File
46 lines
1.1 KiB
Matlab
Executable File
function varargout = atan(varargin)
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%ATAN (overloaded)
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switch class(varargin{1})
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case 'sdpvar'
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varargout{1} = InstantiateElementWise(mfilename,varargin{:});
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case 'char'
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operator = struct('convexity','none','monotonicity','increasing','definiteness','none','model','callback');
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operator.convexhull = @convexhull;
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operator.bounds = @bounds;
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operator.derivative = @(x)((1+x.^2).^-1);
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operator.inverse = @(x)(tan(x));
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operator.range = [-pi/2 pi/2];
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varargout{1} = [];
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varargout{2} = operator;
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varargout{3} = varargin{3};
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otherwise
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error('SDPVAR/ATAN called with CHAR argument?');
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end
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function [L,U] = bounds(xL,xU)
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L = atan(xL);
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U = atan(xU);
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function [Ax, Ay, b] = convexhull(xL,xU)
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fL = atan(xL);
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fU = atan(xU);
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dfL = 1/(1+xL^2);
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dfU = 1/(1+xU^2);
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if xL >= 0
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% Concave region
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[Ax,Ay,b] = convexhullConcave(xL,xU,fL,fU,dfL,dfU);
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elseif xU <= 0
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% Convex region
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[Ax,Ay,b] = convexhullConvex(xL,xU,fL,fU,dfL,dfU);
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else
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% Changes convexity. We're lazy and let YALMIP sample instead
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Ax = [];
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Ay = [];
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b = [];
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end |