anchor.diff:          IMPLICIT DOUBLE PRECISION (A-H,O-Z)
           DIMENSION X(N),W(N)
           N0=(N+1)/2
  +        PF=0.0D0
  +        PD=0.0D0
           DO 45 NR=1,N0
              Z=DCOS(3.1415926D0*(NR-0.25D0)/N)
   10         Z0=Z
  
positive.code:         ID=7
          A1=A-1.0D0
          B1=B-A-1.0D0
          C=12.0/X
          DO 20 M=10,100,5
             HU1=0.0D0
             G=0.5D0*C/M
  
negative.code:            ENDIF
             F2=0.0D0
             F1=1.0D-100
             F=0.0D0
             DO 30 K=M,0,-1
                F=2.0D0*(K+1.0D0)/X*F1-F2
                IF (K.LE.NM) BJ(K)=F
  