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  • Committer: Bazaar Package Importer
  • Author(s): Torsten Werner
  • Date: 2002-03-21 16:57:43 UTC
  • Revision ID: james.westby@ubuntu.com-20020321165743-e9mv12c1tb1plztg
Tags: upstream-2.6
Import upstream version 2.6

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routines/signal/trbize.f
 
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      subroutine trbize(nmaxi,maxdeg,nzm,nzero,sm,zm,zzr,zzi)
 
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c!purpose
 
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c bilinear transformation of the zeros and the locations of the extrema
 
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c!
 
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c
 
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      implicit double precision (a-h,o-z)
 
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      dimension nzm(*)
 
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      dimension sm(maxdeg,*), nzero(*)
 
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      double precision zm(maxdeg,*), zzr(*), zzi(*)
 
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      external slamch, dlamch
 
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      real slamch
 
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c
 
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      flma=2.0d+0**(int(slamch('l'))-2)
 
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      flmi=2.0d+0*dlamch('p')
 
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      fa = 1.0d+0
 
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        do 50 j=1,4
 
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        me = nzm(j)
 
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        do 40 i=1,me
 
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          qi = sm(i,j)
 
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          zm(i,j) = 2.0d+0*atan(qi)
 
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          if (j.ne.4) go to 40
 
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          if (qi.ge.flma) go to 10
 
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          if (qi.lt.flmi) go to 20
 
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          qqi = qi*qi
 
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          q = 1.0d+0 + qqi
 
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          zzr(i) = (1.0d+0-qqi)/q
 
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          zzi(i) = 2.0d+0*qi/q
 
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          nu = nzero(i)/2
 
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          fa = fa*q**nu
 
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          go to 40
 
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c
 
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  10      zzr(i) = -1.0d+0
 
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          go to 30
 
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c
 
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  20      zzr(i) = 1.0d+0
 
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   30      zzi(i) = 0.0d+0
 
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  40    continue
 
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  50  continue
 
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c
 
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      sm(nmaxi-1,1) = fa
 
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      return
 
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      end