C GQUAD     SOURCE    CHAT      05/01/13    00:19:19     5004
      FUNCTION GQUAD(F,A,B,N)
      IMPLICIT INTEGER(I-N)
      IMPLICIT REAL*8(A-H,O-Z)
      EXTERNAL F
      DIMENSION X(1),W(1)
C
C     ******************************************************************
C
C     GQUAD IS SET EQUAL TO THE INTEGRAL OF THE FUNCTION F OVER THE IN-
C     TERVAL (A,B), AS APPROXIMATED BY THE GAUSS-LEGENDRE QUADRATURE
C     FORMULA OF ORDER N.
C
C     CALLS ... SUBROUTINE D106XX.
C
C     ******************************************************************
C
      CALL D106XX(1,F,A,B,N,X,W)
      GQUAD=X(1)
      RETURN
      END