      SUBROUTINE MVPRD(M,N,A,IA,JA,X,Y)
C     ******************************************************************
C     PRODUCT OF A SPARSE MATRIX AND A VECTOR
C     ******************************************************************
      REAL A(1), X(N), Y(M)
      INTEGER IA(1), JA(1)
      DOUBLE PRECISION DSUM
C
      DO 11 I = 1,M
      DSUM = 0.D0
      JMIN = IA(I)
      JMAX = IA(I+1) - 1
      IF (JMIN .GT. JMAX) GO TO 11
         DO 10 J = JMIN,JMAX
         JCOL = JA(J)
   10    DSUM = DSUM + DBLE(A(J))*DBLE(X(JCOL))
   11 Y(I) = DSUM
      RETURN
      END
