www.gusucode.com > 时间序列分析工具箱 - tsa源码程序 > tsa/sbispec.m
function sbispec(BISPEC) % SBISPEC show BISPECTRUM % Version 0.23 % last revision 21.03.1998 % Copyright (C) 1997, 1998 by Alois Schloegl <a.schloegl@ieee.org> % This library is free software; you can redistribute it and/or % modify it under the terms of the GNU Library General Public % License as published by the Free Software Foundation; either % Version 2 of the License, or (at your option) any later version. % % This library is distributed in the hope that it will be useful, % but WITHOUT ANY WARRANTY; without even the implied warranty of % MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU % Library General Public License for more details. % % You should have received a copy of the GNU Library General Public % License along with this library; if not, write to the % Free Software Foundation, Inc., 59 Temple Place - Suite 330, % Boston, MA 02111-1307, USA. [s1,s2]=size(BISPEC); t1=(0:s1-1)/max(s1); t2=(0:s2/2-1)/max(s2); tmp=tril(NaN*ones(s1,s2),-1); BISPEC=BISPEC+tmp+rot90(tmp); BISPEC=BISPEC(1:s1/2,:); subplot(211); mesh(t1,t2,abs(BISPEC)); title('Bispectrum - mesh plot'); subplot(212); contour(t1,t2,abs(BISPEC)); %contour(t1,t2,log(abs(BISPEC))); title('Bispectrum - contour plot');