d9/d32/dgamr_8f_source.html

 *DECK DGAMR

       DOUBLE PRECISION FUNCTION dgamr (X)

 C***BEGIN PROLOGUE  DGAMR

 C***PURPOSE  Compute the reciprocal of the Gamma function.

 C***LIBRARY   SLATEC (FNLIB)

 C***CATEGORY  C7A

 C***TYPE      DOUBLE PRECISION (GAMR-S, DGAMR-D, CGAMR-C)

 C***KEYWORDS  FNLIB, RECIPROCAL GAMMA FUNCTION, SPECIAL FUNCTIONS

 C***AUTHOR  Fullerton, W., (LANL)

 C***DESCRIPTION

 C

 C DGAMR(X) calculates the double precision reciprocal of the

 C complete Gamma function for double precision argument X.

 C

 C***REFERENCES  (NONE)

 C***ROUTINES CALLED  DGAMMA, DLGAMS, XERCLR, XGETF, XSETF

 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   900727  Added EXTERNAL statement.  (WRB)

 C***END PROLOGUE  DGAMR

       DOUBLE PRECISION X, ALNGX, SGNGX, DGAMMA

       EXTERNAL dgamma

 C***FIRST EXECUTABLE STATEMENT  DGAMR

       dgamr = 0.0d0

       IF (x.LE.0.0d0 .AND. aint(x).EQ.x) RETURN

 C

       CALL xgetf(irold)

       CALL xsetf(1)

       IF (abs(x).GT.10.0d0) go to 10

       dgamr = 1.0d0/dgamma(x)

       CALL xerclr

       CALL xsetf(irold)

       RETURN

 C

  10   CALL dlgams(x, alngx, sgngx)

       CALL xerclr

       CALL xsetf(irold)

       dgamr = sgngx * exp(-alngx)

       RETURN

 C

       END

dlgams
subroutine dlgams(X, DLGAM, SGNGAM)
Definition: dlgams.f:2

dgamr
double precision function dgamr(X)
Definition: dgamr.f:2

xsetf
subroutine xsetf(KONTRL)
Definition: xsetf.f:2

base_det::exp
int exp(void) const
Definition: DET.h:66

xgetf
subroutine xgetf(KONTRL)
Definition: xgetf.f:2

to
may be zero for pure relative error test tem the relative tolerance must be greater than or equal to
Definition: Quad-opts.cc:233

abs
OCTAVE_EXPORT octave_value_list return the value of the option it must match the dimension of the state and the relative tolerance must also be a vector of the same length tem it must match the dimension of the state and the absolute tolerance must also be a vector of the same length The local error test applied at each integration step is xample roup abs(local error in x(i))<

xerclr
subroutine xerclr
Definition: xerclr.f:2