gami.f
FUNCTION GAMI (A, X)
C***BEGIN PROLOGUE GAMI
C***PURPOSE Evaluate the incomplete Gamma function.
C***LIBRARY SLATEC (FNLIB)
C***CATEGORY C7E
C***TYPE SINGLE PRECISION (GAMI-S, DGAMI-D)
C***KEYWORDS FNLIB, INCOMPLETE GAMMA FUNCTION, SPECIAL FUNCTIONS
C***AUTHOR Fullerton, W., (LANL)
C***DESCRIPTION
C
C Evaluate the incomplete gamma function defined by
C
C GAMI = integral from T = 0 to X of EXP(-T) * T**(A-1.0) .
C
C GAMI is evaluated for positive values of A and non-negative values
C of X. A slight deterioration of 2 or 3 digits accuracy will occur
C when GAMI is very large or very small, because logarithmic variables
C are used. GAMI, A, and X are single precision.
C
C***REFERENCES (NONE)
C***ROUTINES CALLED ALNGAM, GAMIT, XERMSG
C***REVISION HISTORY (YYMMDD)
C 770701 DATE WRITTEN
C 890531 Changed all specific intrinsics to generic. (WRB)
C 890531 REVISION DATE from Version 3.2
C 891214 Prologue converted to Version 4.0 format. (BAB)
C 900315 CALLs to XERROR changed to CALLs to XERMSG. (THJ)
C***END PROLOGUE GAMI