www.gusucode.com > wavelet工具箱matlab源码程序 > wavelet/wavelet/@wptree/wpthcoef.m
function t = wpthcoef(t,keepapp,sorh,thr) %WPTHCOEF Wavelet packet coefficients thresholding. % NEWT = WPTHCOEF(T,KEEPAPP,SORH,THR) % returns the new wavelet packet tree NEWT % obtained from the wavelet packet tree T % by coefficients thresholding. % % If KEEPAPP = 1, approximation coefficients are not % thresholded, otherwise it is possible. % If SORH = 's', soft thresholding is applied, % if SORH = 'h', hard thresholding is applied (see WTHRESH). % % THR is the threshold value. % % See also WPDEC, WPDEC2, WPDENCMP, WTHRESH. % M. Misiti, Y. Misiti, G. Oppenheim, J.M. Poggi 12-Mar-96. % Last Revision: 14-May-2003. % Copyright 1995-2004 The MathWorks, Inc. tnods = leaves(t); % Keep terminal nodes. % Sort terminal nodes % from left to right. % Approximation index is 1. if keepapp==1 % Save approximation. app_coefs = read(t,'data',tnods(1)); end coefs = read(t,'data'); coefs = wthresh(coefs,sorh,thr); t = write(t,'data',coefs); if keepapp==1 % Restore approximation. t = write(t,'data',tnods(1),app_coefs); end