C QL3 10
C ..................................................................QL3 20
C QL3 30
C SUBROUTINE QL3 QL3 40
C QL3 50
C PURPOSE QL3 60
C TO COMPUTE INTEGRAL(EXP(-X)*FCT(X), SUMMED OVER X FROM 0 QL3 70
C TO INFINITY). QL3 80
C QL3 90
C USAGE QL3 100
C CALL QL3 (FCT,Y) QL3 110
C PARAMETER FCT REQUIRES AN EXTERNAL STATEMENT QL3 120
C QL3 130
C DESCRIPTION OF PARAMETERS QL3 140
C FCT - THE NAME OF AN EXTERNAL FUNCTION SUBPROGRAM USED. QL3 150
C Y - THE RESULTING INTEGRAL VALUE. QL3 160
C QL3 170
C REMARKS QL3 180
C NONE QL3 190
C QL3 200
C SUBROUTINES AND FUNCTION SUBPROGRAMS REQUIRED QL3 210
C THE EXTERNAL FUNCTION SUBPROGRAM FCT(X) MUST BE FURNISHED QL3 220
C BY THE USER. QL3 230
C QL3 240
C METHOD QL3 250
C EVALUATION IS DONE BY MEANS OF 3-POINT GAUSSIAN-LAGUERRE QL3 260
C QUADRATURE FORMULA, WHICH INTEGRATES EXACTLY WHENEVER QL3 270
C FCT(X) IS A POLYNOMIAL UP TO DEGREE 5. QL3 280
C FOR REFERENCE, SEE QL3 290
C V.I.KRYLOV, APPROXIMATE CALCULATION OF INTEGRALS, QL3 300
C MACMILLAN, NEW YORK/LONDON, 1962, PP.130-132 AND 347-352. QL3 310
C QL3 320
C ..................................................................QL3 330
C QL3 340
SUBROUTINE QL3(FCT,Y) QL3 350
C QL3 360
C QL3 370
X=6.289945 QL3 380
Y=.01038926*FCT(X) QL3 390
X=2.294280 QL3 400
Y=Y+.2785177*FCT(X) QL3 410
X=.4157746 QL3 420
Y=Y+.7110930*FCT(X) QL3 430
RETURN QL3 440
END QL3 450