SUBROUTINE DVY0 (M, X, F, WORK, IWORK, INFO)
C***BEGIN PROLOGUE  DVY0
C***PURPOSE  Computes the Bessel function of the second kind
C            of order zero (Y0) for a vector of real arguments
C***LIBRARY   VFNLIB
C***CATEGORY  C10A1
C***TYPE      DOUBLE PRECISION (VY0-S, DVY0-D)
C***KEYWORDS  BESSEL FUNCTION,SECOND KIND, ORDER ZERO, VECTORIZED
C***AUTHOR  SAUNDERS, B. V., (NIST)
C             COMPUTING AND APPLIED MATHEMATICS LABORATORY
C             NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY
C             GAITHERSBURG, MD 20899
C           BOISVERT, R. F., (NIST)
C             COMPUTING AND APPLIED MATHEMATICS LABORATORY
C             NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY
C             GAITHERSBURG, MD 20899
C***DESCRIPTION
C
C   DVY0 computes the  Bessel function of the second kind of order
C   zero (Y0) for real arguments using uniform approximation by
C   Chebyshev polynomials.
C
C
C   P A R A M E T E R S
C
C   M      (Input) Integer (M .GT. 0)
C          The number of arguments at which the function is to be
C          evaluated.
C
C   X      (Input) Double precision array of length M
C          The arguments at which the function is to be evaluated are
C          stored in X(1) to X(M) in any order.
C
C   F      (Output) Double precision array of length M
C          F(i) contains the value of the function at X(i), i=1,..,M.
C
C   WORK   (Work) Double precision vector of length 7*M
C
C   IWORK  (Work) Integer vector of length M
C
C   INFO   (Output) Integer
C          Indicates status of computed result. The following table
C          lists possible values and their meanings.  If OK=Yes then
C          all F(i) have been set, otherwise none have been set.
C
C          INFO  OK            Description
C          ------------------------------------------------------------
C            0   Yes  Successfull execution.
C            1   No   Error: M .LE. 0
C            2   No   Error: X(i) zero or negative for some i
C            3   No   Error: Some X(i) so big that no precision possible
C                     in computing Y0. The index of the first offending
C                     argument is returned in IWORK(1).
C
C
C *********************************************************************
C   This routine is a modification of the function DBESY0 developed by
C   W. Fullerton of LANL.
C *********************************************************************
C
C***REFERENCES  (NONE)
C***ROUTINES CALLED  DWY0
C***REVISION HISTORY  (YYMMDD)
C   910226  DATE WRITTEN
C***END PROLOGUE  DVY0
C
C     ----------
C     PARAMETERS
C     ----------
C
      INTEGER INFO, IWORK, M
      DOUBLE PRECISION F, X, WORK
C
      DIMENSION X(M), F(M), WORK(7*M), IWORK(M)
C
C     ---------------
C     LOCAL VARIABLES
C     ---------------
C
      INTEGER IWB0, IWB1, IWB2, IWTC, IWXC, IWYC, IWZC, JIN
C
C
C***FIRST EXECUTABLE STATEMENT  DVY0
C
C     ... PARTITION WORK ARRAYS
C
      IWTC   = 1
      IWXC  = IWTC + M
      IWYC  = IWXC + M
      IWZC  = IWYC + M
      IWB0  = IWZC + M
      IWB1  = IWB0 + M
      IWB2  = IWB1 + M
C     Total = IB2  + M
C
      JIN   = 1
C     Total = JIN  + M
C
C     ... DWY0 DOES ALL THE WORK
C
      CALL DWY0(M,X,F,WORK(IWTC),WORK(IWXC),WORK(IWYC),WORK(IWZC),
     +         IWORK(JIN),WORK(IWB0),WORK(IWB1),WORK(IWB2),INFO)
C
      RETURN
      END