C QA2 10
C ..................................................................QA2 20
C QA2 30
C SUBROUTINE QA2 QA2 40
C QA2 50
C PURPOSE QA2 60
C TO COMPUTE INTEGRAL(EXP(-X)*FCT(X)/SQRT(X), SUMMED OVER X QA2 70
C FROM 0 TO INFINITY). QA2 80
C QA2 90
C USAGE QA2 100
C CALL QA2 (FCT,Y) QA2 110
C PARAMETER FCT REQUIRES AN EXTERNAL STATEMENT QA2 120
C QA2 130
C DESCRIPTION OF PARAMETERS QA2 140
C FCT - THE NAME OF AN EXTERNAL FUNCTION SUBPROGRAM USED. QA2 150
C Y - THE RESULTING INTEGRAL VALUE. QA2 160
C QA2 170
C REMARKS QA2 180
C NONE QA2 190
C QA2 200
C SUBROUTINES AND FUNCTION SUBPROGRAMS REQUIRED QA2 210
C THE EXTERNAL FUNCTION SUBPROGRAM FCT(X) MUST BE FURNISHED QA2 220
C BY THE USER. QA2 230
C QA2 240
C METHOD QA2 250
C EVALUATION IS DONE BY MEANS OF 2-POINT GENERALIZED GAUSSIAN-QA2 260
C LAGUERRE QUADRATURE FORMULA, WHICH INTEGRATES EXACTLY, QA2 270
C WHENEVER FCT(X) IS A POLYNOMIAL UP TO DEGREE 3. QA2 280
C FOR REFERENCE, SEE QA2 290
C CONCUS/CASSATT/JAEHNIG/MELBY, TABLES FOR THE EVALUATION OF QA2 300
C INTEGRAL(X**BETA*EXP(-X)*F(X), SUMMED OVER X FROM 0 TO QA2 310
C INFINITY) BY GAUSS-LAGUERRE QUADRATURE, MTAC, VOL.17, QA2 320
C ISS.83 (1963), PP.245-256. QA2 330
C QA2 340
C ..................................................................QA2 350
C QA2 360
SUBROUTINE QA2(FCT,Y) QA2 370
C QA2 380
C QA2 390
X=2.724745 QA2 400
Y=.1626257*FCT(X) QA2 410
X=.2752551 QA2 420
Y=Y+1.609828*FCT(X) QA2 430
RETURN QA2 440
END QA2 450