1 c===========================================================================
3 c This file is part of TISEAN
5 c Copyright (c) 1998-2007 Rainer Hegger, Holger Kantz, Thomas Schreiber
7 c TISEAN is free software; you can redistribute it and/or modify
8 c it under the terms of the GNU General Public License as published by
9 c the Free Software Foundation; either version 2 of the License, or
10 c (at your option) any later version.
12 c TISEAN is distributed in the hope that it will be useful,
13 c but WITHOUT ANY WARRANTY; without even the implied warranty of
14 c MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 c GNU General Public License for more details.
17 c You should have received a copy of the GNU General Public License
18 c along with TISEAN; if not, write to the Free Software
19 c Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
21 c===========================================================================
22 c Wiener filter x according to spectrum a
23 c (routine needed by surrogates.f)
24 C author Thomas Schreiber (1998)
25 c===========================================================================
26 function tospec(nmax,a,x,ibin)
28 dimension x(nmax), a(nmax), w(nx), w1(nx), w2(nx), iw(15)
31 if(nmax.gt.nx) stop "tospec: make nx larger."
34 call rffti1(nmax,w2,iw)
35 call rfftf1(nmax,x,w1,w2,iw)
37 20 x(n)=x(n)/real(nmax)
38 x(1)=x(1)*(a(1)/x(1)**2)
39 do 30 i=2+ibin,(nmax+1)/2-ibin,2*ibin+1
41 do 40 ib=i-ibin,i+ibin
42 40 p=p+x(2*ib-2)**2+x(2*ib-1)**2
44 do 30 ib=i-ibin,i+ibin
45 x(2*ib-2)=x(2*ib-2)*ab
46 30 x(2*ib-1)=x(2*ib-1)*ab
47 if(mod(nmax,2).eq.0) x(nmax)=x(nmax)*(a(nmax)/x(nmax)**2)
48 call rfftb1(nmax,x,w1,w2,iw)
51 50 tospec=tospec+(x(n)-w(n))**2
52 tospec=sqrt(tospec/nmax)