32 lines
796 B
Matlab
Executable File
32 lines
796 B
Matlab
Executable File
function varargout = expint(varargin)
|
|
%EXPINT (overloaded)
|
|
|
|
% Author Johan Löfberg
|
|
switch class(varargin{1})
|
|
|
|
case 'sdpvar'
|
|
varargout{1} = InstantiateElementWise(mfilename,varargin{:});
|
|
|
|
case 'char'
|
|
|
|
varargout{1} = [];
|
|
varargout{2} = createOperator;
|
|
varargout{3} = varargin{3};
|
|
|
|
otherwise
|
|
error('SDPVAR/EXPINT called with CHAR argument?');
|
|
end
|
|
|
|
function operator = createOperator
|
|
|
|
operator = struct('convexity','convex','monotonicity','decreasing','definiteness','positive','model','callback');
|
|
operator.bounds = @bounds;
|
|
operator.derivative = @(x)(-exp(-x)./x);
|
|
operator.range = [0 inf];
|
|
operator.domain = [1e-8 inf];
|
|
|
|
% Bounding functions for the branch&bound solver
|
|
function [L,U] = bounds(xL,xU)
|
|
L = expint(xU);
|
|
U = expint(xL);
|