Sources Esope | Cast3M

foncg
C FONCG     SOURCE    CHAT      05/01/13    00:06:05     5004
C
C*********************************************************************
C
      FUNCTION FONCG(Q,X,Y,Z,X0)
      IMPLICIT INTEGER(I-N)
      IMPLICIT REAL*8(A-H,O-Z)
      EPSIL2=1.D-8
      D=X-X0
      IF(D.EQ.0.) THEN
         X=X+EPSIL2
      ENDIF
      DELTA=SQRT((X-X0)**2+Y**2+(Q*X+Z)**2)
C****
      DELTA1=MAX(DELTA-(Q*X+Z),EPSIL2)
      DELTA3=MAX(DELTA+(Q*X+Z),EPSIL2)
      DELTA2=MAX(Y+DELTA,EPSIL2)
      FONCG=0.5*Y*LOG(DELTA1/DELTA3)
     &     -(Q*X+Z)*LOG(DELTA2)
     &     +(X-X0)*ATAN(Y*(Q*X+Z)/(X-X0)/DELTA)
C****
      RETURN
      END