CUOIK(3)

SYNOPSIS
SUBROUTINE CUOIK (Z, FNU, KODE, IKFLG, N, Y, NUF, TOL, ELIM, ALIM)

NAME
cuoik - Subsidiary to CBESH, CBESI and CBESK

LIBRARY
SLATEC

TYPE
ALL (CUOIK-A, ZUOIK-A)

AUTHOR
Amos, D. E., (SNL)

DESCRIPTION
CUOIK COMPUTES THE LEADING TERMS OF THE UNIFORM ASYMPTOTIC EXPANSIONS FOR THE I AND K FUNCTIONS AND COMPARES THEM (IN LOGARITHMIC FORM) TO ALIM AND ELIM FOR OVER AND UNDERFLOW WHERE ALIM.LT.ELIM. IF THE MAGNITUDE, BASED ON THE LEADING EXPONENTIAL, IS LESS THAN ALIM OR GREATER THAN -ALIM, THEN THE RESULT IS ON SCALE. IF NOT, THEN A REFINED TEST USING OTHER MULTIPLIERS (IN LOGARITHMIC FORM) IS MADE BASED ON ELIM. HERE EXP(-ELIM)=SMALLEST MACHINE NUMBER*1.0E+3 AND EXP(-ALIM)= EXP(-ELIM)/TOL IKFLG=1 MEANS THE I SEQUENCE IS TESTED =2 MEANS THE K SEQUENCE IS TESTED NUF = 0 MEANS THE LAST MEMBER OF THE SEQUENCE IS ON SCALE =-1 MEANS AN OVERFLOW WOULD OCCUR IKFLG=1 AND NUF.GT.0 MEANS THE LAST NUF Y VALUES WERE SET TO ZERO THE FIRST N-NUF VALUES MUST BE SET BY ANOTHER ROUTINE IKFLG=2 AND NUF.EQ.N MEANS ALL Y VALUES WERE SET TO ZERO IKFLG=2 AND 0.LT.NUF.LT.N NOT CONSIDERED. Y MUST BE SET BY ANOTHER ROUTINE

SEE ALSO
CBESH, CBESI, CBESK

ROUTINES CALLED
CUCHK, CUNHJ, CUNIK, R1MACH

REVISION HISTORY (YYMMDD)
830501 DATE WRITTEN
910415 Prologue converted to Version 4.0 format. (BAB)