function?[ts]?=?inverse_st（st）
%?Returns?the?inverse?of?the?Stockwell?Transform?of?the?REAL_VALUED?timeseries.
%?Code?by?Robert?Glenn?Stockwell.
%?Reference?is?“Localization?of?the?Complex?Spectrum:?The?S?Transform“
%?from?IEEE?Transactions?on?Signal?Processing?vol.?44.?number?4?April?1996?pages?998-1001.
%
%-------Inputs?Needed------------------------------------------------
%??
%??S-Transform?matrix?created?by?the?st.m?function
%-------Optional?Inputs?------------------------------------------------
%?none
%-------Outputs?Returned------------------------------------------------
%
%?ts?????-a?REAL-VALUED?time?series
%--------Additional?details-----------------------
%???Copyright?（c）?by?Bob?Stockwell
%???$Revision:?1.0?$??$Date:?2004/10/10??$

%?sum?over?time?to?create?the?FFT?spectrum?for?the?positive?frequencies
stspe?=?sum（st2）;

%?get?st?matrix?dimensions?
[nfreqntimes]?=?size（st）;
if?rem（ntimes?2）?~=?0
????%?odd?number?of?points?so?nyquist?point?is?not?aliased?so?concatenate
????%?the?reversed?spectrum?to?create?the?negative?frequencies
????%?drop?the?DC?value
????negspe?=?fliplr（stspe（2:nfreq）‘）;
else
?????%?even?number?of?points
?????%?therefore?drop?the?first?point?（DC）?and?the?last?point?（aliased?nyqusit?freq）
?????negspe?=?fliplr（stspe（2:nfreq-1）‘）;
end

%?using?symmetry?of?FFT?spectrum?of?a?real?signal?recreate?the?negative?frequencies?from?the?positie?frequencies
?fullstspe?=?[conj（stspe‘）??negspe];????

%?the?time?series?is?the?inverse?fft?of?this
ts?=?ifft（fullstspe）;
%?and?take?the?real?part?the?imaginary?part?will?be?zero.
ts?=?real（ts）;

?屬性????????????大小?????日期????時(shí)間???名稱
-----------?---------??----------?-----??----

?????文件???????1637??2008-04-08?22:07??S-Transform\inverse_st.m

?????文件????????936??2008-04-08?22:06??S-Transform\s-tranform?test.m

?????文件?????797303??2008-04-19?16:33??S-Transform\S-Trans.pdf

?????文件??????13712??2008-04-08?22:05??S-Transform\S-Transform.m

?????文件???????1152??2008-04-08?22:08??S-Transform\st_inverse_test.m

?????目錄??????????0??2008-04-20?20:15??S-Transform

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???????????????814958????????????????????7