SUBROUTINE DVJ0 (M, X, F, WORK, IWORK, INFO) C***BEGIN PROLOGUE DVJ0 C***PURPOSE Computes the Bessel function of the first kind of order C zero (J0) for a vector of real arguments C***LIBRARY VFNLIB C***CATEGORY C10B1 C***TYPE DOUBLE PRECISION (VJ0-S, DVJ0-D) C***KEYWORDS BESSEL FUNCTION,FIRST KIND, ORDER ZERO, SPECIAL FUNCTION, C 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 DVJ0 computes the Bessel function of the first kind of order zero C (J0) for real arguments using uniform approximation by Chebyshev C 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: Some abs(X(i)) so big that no precision C possible in computing J0. The index of the C first offending argument is returned in IWORK(1). C C ********************************************************************* C This routine is a modification of the function DBESJ0 developed by C W. Fullerton of LANL. C ********************************************************************* C C***REFERENCES (NONE) C***ROUTINES CALLED DWJ0 C***REVISION HISTORY (YYMMDD) C 910226 DATE WRITTEN