zuoik.f
SUBROUTINE ZUOIK (ZR, ZI, FNU, KODE, IKFLG, N, YR, YI, NUF, TOL,
+ ELIM, ALIM)
C***BEGIN PROLOGUE ZUOIK
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Warning: this routine is not intended to be user-callable.
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C***SUBSIDIARY
C***PURPOSE Subsidiary to ZBESH, ZBESI and ZBESK
C***LIBRARY SLATEC
C***TYPE ALL (CUOIK-A, ZUOIK-A)
C***AUTHOR Amos, D. E., (SNL)
C***DESCRIPTION
C
C ZUOIK COMPUTES THE LEADING TERMS OF THE UNIFORM ASYMPTOTIC
C EXPANSIONS FOR THE I AND K FUNCTIONS AND COMPARES THEM
C (IN LOGARITHMIC FORM) TO ALIM AND ELIM FOR OVER AND UNDERFLOW
C WHERE ALIM.LT.ELIM. IF THE MAGNITUDE, BASED ON THE LEADING
C EXPONENTIAL, IS LESS THAN ALIM OR GREATER THAN -ALIM, THEN
C THE RESULT IS ON SCALE. IF NOT, THEN A REFINED TEST USING OTHER
C MULTIPLIERS (IN LOGARITHMIC FORM) IS MADE BASED ON ELIM. HERE
C EXP(-ELIM)=SMALLEST MACHINE NUMBER*1.0E+3 AND EXP(-ALIM)=
C EXP(-ELIM)/TOL
C
C IKFLG=1 MEANS THE I SEQUENCE IS TESTED
C =2 MEANS THE K SEQUENCE IS TESTED
C NUF = 0 MEANS THE LAST MEMBER OF THE SEQUENCE IS ON SCALE
C =-1 MEANS AN OVERFLOW WOULD OCCUR
C IKFLG=1 AND NUF.GT.0 MEANS THE LAST NUF Y VALUES WERE SET TO ZERO
C THE FIRST N-NUF VALUES MUST BE SET BY ANOTHER ROUTINE
C IKFLG=2 AND NUF.EQ.N MEANS ALL Y VALUES WERE SET TO ZERO
C IKFLG=2 AND 0.LT.NUF.LT.N NOT CONSIDERED. Y MUST BE SET BY
C ANOTHER ROUTINE
C
C***SEE ALSO ZBESH, ZBESI, ZBESK
C***ROUTINES CALLED D1MACH, ZABS, ZLOG, ZUCHK, ZUNHJ, ZUNIK
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 ZUOIK