home
***
CD-ROM
|
disk
|
FTP
|
other
***
search
/
Frostbyte's 1980s DOS Shareware Collection
/
floppyshareware.zip
/
floppyshareware
/
DOOG
/
PCSSP1.ZIP
/
AGLGQUAD.ZIP
/
QA10.FOR
< prev
next >
Wrap
Text File
|
1985-11-29
|
2KB
|
62 lines
C
C ..................................................................
C
C SUBROUTINE QA10
C
C PURPOSE
C TO COMPUTE INTEGRAL(EXP(-X)*FCT(X)/SQRT(X), SUMMED OVER X
C FROM 0 TO INFINITY).
C
C USAGE
C CALL QA10 (FCT,Y)
C PARAMETER FCT REQUIRES AN EXTERNAL STATEMENT
C
C DESCRIPTION OF PARAMETERS
C FCT - THE NAME OF AN EXTERNAL FUNCTION SUBPROGRAM USED.
C Y - THE RESULTING INTEGRAL VALUE.
C
C REMARKS
C NONE
C
C SUBROUTINES AND FUNCTION SUBPROGRAMS REQUIRED
C THE EXTERNAL FUNCTION SUBPROGRAM FCT(X) MUST BE FURNISHED
C BY THE USER.
C
C METHOD
C EVALUATION IS DONE BY MEANS OF 10-POINT GENERALIZED GAUSS-
C LAGUERRE QUADRATURE FORMULA, WHICH INTEGRATES EXACTLY,
C WHENEVER FCT(X) IS A POLYNOMIAL UP TO DEGREE 19.
C FOR REFERENCE, SEE
C CONCUS/CASSATT/JAEHNIG/MELBY, TABLES FOR THE EVALUATION OF
C INTEGRAL(X**BETA*EXP(-X)*F(X), SUMMED OVER X FROM 0 TO
C INFINITY) BY GAUSS-LAGUERRE QUADRATURE, MTAC, VOL.17,
C ISS.83 (1963), PP.245-256.
C
C ..................................................................
C
SUBROUTINE QA10(FCT,Y)
C
C
X=29.02495
Y=.4458787E-12*FCT(X)
X=21.19389
Y=Y+.8798682E-9*FCT(X)
X=15.56116
Y=Y+.2172139E-6*FCT(X)
X=11.20813
Y=Y+.1560511E-4*FCT(X)
X=7.777439
Y=Y+.0004566773*FCT(X)
X=5.084908
Y=Y+.006487547*FCT(X)
X=3.022513
Y=Y+.04962104*FCT(X)
X=1.522944
Y=Y+.2180344*FCT(X)
X=.5438675
Y=Y+.5733510*FCT(X)
X=.06019206
Y=Y+.9244873*FCT(X)
RETURN
END