这里面有很多有用的东东

				function A=add(A)
				%ADD	
				%Add multiple of one row of a matrix to another row.
				%Used in row reduction.
				%Calling format: A=add(A)
				 
				%Copyright Gareth Williams, Stetson University 
				%gwilliam@stetson.edu, http://www.stetson.edu/~gwilliam
				%Accompanies "Linear Algebra with Applications" by Gareth Williams
				
				disp(' ')
				a=input('add the multiple: ');
				m=input('          of row: ');
				n=input('          to row: ');
				A(n,:) = A(n,:) + a*A(m,:);
				disp(' ')