C DQL4 10
C ..................................................................DQL4 20
C DQL4 30
C SUBROUTINE DQL4 DQL4 40
C DQL4 50
C PURPOSE DQL4 60
C TO COMPUTE INTEGRAL(EXP(-X)*FCT(X), SUMMED OVER X DQL4 70
C FROM 0 TO INFINITY). DQL4 80
C DQL4 90
C USAGE DQL4 100
C CALL DQL4 (FCT,Y) DQL4 110
C PARAMETER FCT REQUIRES AN EXTERNAL STATEMENT DQL4 120
C DQL4 130
C DESCRIPTION OF PARAMETERS DQL4 140
C FCT - THE NAME OF AN EXTERNAL DOUBLE PRECISION FUNCTION DQL4 150
C SUBPROGRAM USED. DQL4 160
C Y - THE RESULTING DOUBLE PRECISION INTEGRAL VALUE. DQL4 170
C DQL4 180
C REMARKS DQL4 190
C NONE DQL4 200
C DQL4 210
C SUBROUTINES AND FUNCTION SUBPROGRAMS REQUIRED DQL4 220
C THE EXTERNAL DOUBLE PRECISION FUNCTION SUBPROGRAM FCT(X) DQL4 230
C MUST BE FURNISHED BY THE USER. DQL4 240
C DQL4 250
C METHOD DQL4 260
C EVALUATION IS DONE BY MEANS OF 4-POINT GAUSSIAN-LAGUERRE DQL4 270
C QUADRATURE FORMULA, WHICH INTEGRATES EXACTLY, DQL4 280
C WHENEVER FCT(X) IS A POLYNOMIAL UP TO DEGREE 7. DQL4 290
C FOR REFERENCE, SEE DQL4 300
C SHAO/CHEN/FRANK, TABLES OF ZEROS AND GAUSSIAN WEIGHTS OF DQL4 310
C CERTAIN ASSOCIATED LAGUERRE POLYNOMIALS AND THE RELATED DQL4 320
C GENERALIZED HERMITE POLYNOMIALS, IBM TECHNICAL REPORT DQL4 330
C TR00.1100 (MARCH 1964), PP.24-25. DQL4 340
C DQL4 350
C ..................................................................DQL4 360
C DQL4 370
SUBROUTINE DQL4(FCT,Y) DQL4 380
C DQL4 390
C DQL4 400
DOUBLE PRECISION X,Y,FCT DQL4 410
C DQL4 420
X=.9395070912301133D1 DQL4 430
Y=.53929470556132745D-3*FCT(X) DQL4 440
X=.45366202969211280D1 DQL4 450
Y=Y+.38887908515005384D-1*FCT(X) DQL4 460
X=.17457611011583466D1 DQL4 470
Y=Y+.35741869243779969D0*FCT(X) DQL4 480
X=.32254768961939231D0 DQL4 490
Y=Y+.60315410434163360D0*FCT(X) DQL4 500
RETURN DQL4 510
END DQL4 520