www.gusucode.com > wavelet工具箱matlab源码程序 > wavelet/wavelet/@laurpoly/dyadup.m
function Q = dyadup(P) %DYADUP Dyadic upsampling for a Laurent polynomial. % Q = DYADUP(P) returns the Laurent polynomial Q obtained by % an "upsampling" on the Laurent polynomial P: Q(z) = P(z^2). % if P(z) = ... C(-1)*z^(-1) + C(0) + C(+1)*z^(+1) + ... % then Q(z) = ... C(-1)*z^(-2) + C(0) + C(+1)*z^(+2) + ... % % See also DYADDOWN, MODULATE, NEWVAR, REFLECT. % M. Misiti, Y. Misiti, G. Oppenheim, J.M. Poggi 07-Feb-2003. % Last Revision 13-Jun-2003. % Copyright 1995-2004 The MathWorks, Inc. Q = newvar(P,'z^2');