covsrt.for

Numerical Recipes一书中例子的源码所用到的函数集,William H. Press 和 Saul A. Teukolsky 所著

      SUBROUTINE covsrt(covar,npc,ma,ia,mfit)
      INTEGER ma,mfit,npc,ia(ma)
      REAL covar(npc,npc)
      INTEGER i,j,k
      REAL swap
      do 12 i=mfit+1,ma
        do 11 j=1,i
          covar(i,j)=0.
          covar(j,i)=0.
11      continue
12    continue
      k=mfit
      do 15 j=ma,1,-1
        if(ia(j).ne.0)then
          do 13 i=1,ma
            swap=covar(i,k)
            covar(i,k)=covar(i,j)
            covar(i,j)=swap
13        continue
          do 14 i=1,ma
            swap=covar(k,i)
            covar(k,i)=covar(j,i)
            covar(j,i)=swap
14        continue
          k=k-1
        endif
15    continue
      return
      END