sqrt.m

matlab波形优化算法经常要用到的matlab toolbox工具箱:yalmip

function varargout = SQRT(varargin)
%SQRT (overloaded)
%
% t = sqrt(x)
%
% The variable t can only be used in concavity preserving
% operations such as t>1, max t etc.
%
% When SQRT is used in a problem, the domain constraint
% set(x>0) is automatically added to the problem.
%
% See also SDPVAR, SDPVAR/GEOMEAN

% Author Johan L鰂berg
% $Id: sqrt.m,v 1.8 2008/01/08 08:02:41 joloef Exp $

switch class(varargin{1})

    case 'double' % What is the numerical value of this argument (needed for displays etc)
        X = sqrt(varargin{1});

    case 'sdpvar' % Overloaded operator for SDPVAR objects. Pass on args and save them.
        X = varargin{1};
        [n,m] = size(X);
        if is(varargin{1},'real') & (n*m==1)
            varargout{1} = yalmip('define',mfilename,varargin{:});
        else
            error('SQRT can only be applied to real scalars');
        end

    case 'char' % YALMIP send 'model' when it wants the epigraph or hypograph
        if isequal(varargin{1},'graph')
            t = varargin{2}; % Second arg is the extended operator variable
            X = varargin{3}; % Third arg and above are the args user used when defining t.
            varargout{1} = set(cone([(X-1)/2;t],(X+1)/2));
            varargout{2} = struct('convexity','concave','monotonicity','increasing','definiteness','positive');
            varargout{3} = X;
        elseif isequal(varargin{1},'exact')
            % t = varargin{2}; % Second arg is the extended operator variable
            % X = varargin{3}; % Third arg and above are the args user used when defining t.
            varargout{1} = [];
            varargout{2} = [];
            varargout{3} = [];
        end
    otherwise
end