zseri.f
SUBROUTINE ZSERI (ZR, ZI, FNU, KODE, N, YR, YI, NZ, TOL, ELIM,
+ ALIM)
C***BEGIN PROLOGUE ZSERI
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Warning: this routine is not intended to be user-callable.
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C***SUBSIDIARY
C***PURPOSE Subsidiary to ZBESI and ZBESK
C***LIBRARY SLATEC
C***TYPE ALL (CSERI-A, ZSERI-A)
C***AUTHOR Amos, D. E., (SNL)
C***DESCRIPTION
C
C ZSERI COMPUTES THE I BESSEL FUNCTION FOR REAL(Z).GE.0.0 BY
C MEANS OF THE POWER SERIES FOR LARGE ABS(Z) IN THE
C REGION ABS(Z).LE.2*SQRT(FNU+1). NZ=0 IS A NORMAL RETURN.
C NZ.GT.0 MEANS THAT THE LAST NZ COMPONENTS WERE SET TO ZERO
C DUE TO UNDERFLOW. NZ.LT.0 MEANS UNDERFLOW OCCURRED, BUT THE
C CONDITION ABS(Z).LE.2*SQRT(FNU+1) WAS VIOLATED AND THE
C COMPUTATION MUST BE COMPLETED IN ANOTHER ROUTINE WITH N=N-ABS(NZ).
C
C***SEE ALSO ZBESI, ZBESK
C***ROUTINES CALLED D1MACH, DGAMLN, ZABS, ZDIV, ZLOG, ZMLT, ZUCHK
C***REVISION HISTORY (YYMMDD)
C 830501 DATE WRITTEN
C 910415 Prologue converted to Version 4.0 format. (BAB)
C 930122 Added ZLOG to EXTERNAL statement. (RWC)
C***END PROLOGUE ZSERI