      SUBROUTINE MERGE (TCOS,I1,M1,I2,M2,I3)
      DIMENSION       TCOS(1)
C
C
C     THIS SUBROUTINE MERGES TWO ASCENDING STRINGS OF NUMBERS IN THE
C     ARRAY TCOS.  THE FIRST STRING IS OF LENGTH M1 AND STARTS AT
C     TCOS(I1+1).  THE SECOND STRING IS OF LENGTH M2 AND STARTS AT
C     TCOS(I2+1).  THE MERGED STRING GOES INTO TCOS(I3+1).
C
C
      J1 = 1
      J2 = 1
      J = I3
      IF (M1 .EQ. 0) GO TO 107
      IF (M2 .EQ. 0) GO TO 104
  101 J = J+1
      L = J1+I1
      X = TCOS(L)
      L = J2+I2
      Y = TCOS(L)
      IF (X-Y) 102,102,103
  102 TCOS(J) = X
      J1 = J1+1
      IF (J1 .GT. M1) GO TO 106
      GO TO 101
  103 TCOS(J) = Y
      J2 = J2+1
      IF (J2 .LE. M2) GO TO 101
      IF (J1 .GT. M1) GO TO 109
  104 K = J-J1+1
      DO 105 J=J1,M1
         M = K+J
         L = J+I1
         TCOS(M) = TCOS(L)
  105 CONTINUE
      GO TO 109
  106 CONTINUE
      IF (J2 .GT. M2) GO TO 109
  107 K = J-J2+1
      DO 108 J=J2,M2
         M = K+J
         L = J+I2
         TCOS(M) = TCOS(L)
  108 CONTINUE
  109 CONTINUE
      RETURN
      END
