function a = creation ( m, n ) %*****************************************************************************80 % %% CREATION returns the creation matrix. % % Example: % % M = 5, N = 5 % % 0 0 0 0 0 % 1 0 0 0 0 % 0 2 0 0 0 % 0 0 3 0 0 % 0 0 0 4 0 % % Properties: % % A is integral: int ( A ) = A. % % A is strictly lower triangular. % % Square properties: % % A is generally not symmetric: A' /= A. % % A is singular. % % A has the null vector ( 0, 0, ..., 0, 1 ). % % det ( A ) = 0. % % LAMBDA(1:N) = 0 % % A is zero except for the first lower diagonal. A^2 is zero except for % the second lower diagonal. A^(N-1) is the last nonzero power of A, % with a single nonzero entry in the (N,1) position. % % Licensing: % % This code is distributed under the GNU LGPL license. % % Modified: % % 02 October 2007 % % Author: % % John Burkardt % % Parameters: % % Input, integer M, the number of rows of A. % % Input, integer N, the number of columns of A. % % Output, real A(N,N), the matrix. % for i = 1 : n for j = 1 : n if ( i == j + 1 ) a(i,j) = j; else a(i,j) = 0.0; end end end return end