lubksb(float ** a,int n,int * indx,float b[])1void lubksb(float **a, int n, int *indx, float b[]) 2 { 3 int i,ii=0,ip,j; 4 float sum; 5 6 for (i=1;i<=n;i++) { 7 ip=indx[i]; 8 sum=b[ip]; 9 b[ip]=b[i]; 10 if (ii) 11 for (j=ii;j<=i-1;j++) sum -= a[i][j]*b[j]; 12 else if (sum) ii=i; 13 b[i]=sum; 14 } 15 for (i=n;i>=1;i--) { 16 sum=b[i]; 17 for (j=i+1;j<=n;j++) sum -= a[i][j]*b[j]; 18 b[i]=sum/a[i][i]; 19 } 20 } 21 /* (C) Copr. 1986-92 Numerical Recipes Software 0!-"1. */ 22