39 lines
879 B
Mathematica
39 lines
879 B
Mathematica
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function varargout = acos_internal(varargin)
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%ACOS (overloaded)
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switch class(varargin{1})
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case 'double'
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x = varargin{1};
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y = acos(x);
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y(x<-1) = pi;
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y(x>1) = 0;
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varargout{1} = y;
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case 'char'
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operator = struct('convexity','none','monotonicity','decreasing','definiteness','none','model','callback');
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operator.convexhull = [];
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operator.bounds = @bounds;
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operator.derivative = @derivative;
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operator.range = [-pi/2 pi/2];
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operator.domain = [-1 1];
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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/ACOS called with CHAR argument?');
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end
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function [L,U] = bounds(xL,xU)
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L = real(acos(xU));
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U = real(acos(xL));
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function df = derivative(x)
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df = (-(1 - x.^2).^-0.5);
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df(x>1) = 0;
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df(x<1) = 0;
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