国外专家做的求解LMI鲁棒控制的工具箱,可以相对高效的解决LMI问题

				function Y=diff(varargin)
				%DIFF (overloaded)
				
				% Author Johan L鰂berg 
				% $Id: diff.m,v 1.2 2004/07/01 11:17:09 johanl Exp $   
				
				X = varargin{1};
				n = X.n;
				m = X.m;
				
				Y = X;
				x_lmi_variables = X.lmi_variables;
				lmi_variables = [];
				
				try
					j = 1;
					diffX = diff(reshape(X.basis(:,1),n,m),varargin{2:end});
					Y.basis=diffX(:);
					for i = 1:length(x_lmi_variables)
						diffX = diff(reshape(X.basis(:,i+1),n,m),varargin{2:end});
						if (norm(diffX,inf)>0)
							Y.basis(:,j+1) = diffX(:);
							lmi_variables = [lmi_variables x_lmi_variables(i)];
							j = j+1;
						end
					end   
					if j~=1
						Y.lmi_variables = lmi_variables;
					else
				     Y = full(reshape(Y.basis(:,1),size(diffX,1),size(diffX,2)));
				     return
					end
				catch
					error(lasterr)
				end
				Y.n = size(diffX,1);
				Y.m = size(diffX,2);