C QG10 10
C ..................................................................QG10 20
C QG10 30
C SUBROUTINE QG10 QG10 40
C QG10 50
C PURPOSE QG10 60
C TO COMPUTE INTEGRAL(FCT(X), SUMMED OVER X FROM XL TO XU) QG10 70
C QG10 80
C USAGE QG10 90
C CALL QG10(XL,XU,FCT,Y) QG10 100
C PARAMETER FCT REQUIRES AN EXTERNAL STATEMENT QG10 110
C QG10 120
C DESCRIPTION OF PARAMETERS QG10 130
C XL - THE LOWER BOUND OF THE INTERVAL. QG10 140
C XU - THE UPPER BOUND OF THE INTERVAL. QG10 150
C FCT - THE NAME OF AN EXTERNAL FUNCTION SUBPROGRAM USED. QG10 160
C Y - THE RESULTING INTEGRAL VALUE. QG10 170
C QG10 180
C REMARKS QG10 190
C NONE QG10 200
C QG10 210
C SUBROUTINES AND FUNCTION SUBPROGRAMS REQUIRED QG10 220
C THE EXTERNAL FUNCTION SUBPROGRAM FCT(X) MUST BE FURNISHED QG10 230
C BY THE USER. QG10 240
C QG10 250
C METHOD QG10 260
C EVALUATION IS DONE BY MEANS OF 10-POINT GAUSS QUADRATURE QG10 270
C FORMULA, WHICH INTEGRATES POLYNOMIALS UP TO DEGREE 19 QG10 280
C EXACTLY. QG10 290
C FOR REFERENCE, SEE QG10 300
C V.I.KRYLOV, APPROXIMATE CALCULATION OF INTEGRALS, QG10 310
C MACMILLAN, NEW YORK/LONDON, 1962, PP.100-111 AND 337-338. QG10 320
C QG10 330
C ..................................................................QG10 340
C QG10 350
SUBROUTINE QG10(XL,XU,FCT,Y) QG10 360
C QG10 370
C QG10 380
A=.5*(XU+XL) QG10 390
B=XU-XL QG10 400
C=.4869533*B QG10 410
Y=.03333567*(FCT(A+C)+FCT(A-C)) QG10 420
C=.4325317*B QG10 430
Y=Y+.07472567*(FCT(A+C)+FCT(A-C)) QG10 440
C=.3397048*B QG10 450
Y=Y+.1095432*(FCT(A+C)+FCT(A-C)) QG10 460
C=.2166977*B QG10 470
Y=Y+.1346334*(FCT(A+C)+FCT(A-C)) QG10 480
C=.07443717*B QG10 490
Y=B*(Y+.1477621*(FCT(A+C)+FCT(A-C))) QG10 500
RETURN QG10 510
END QG10 520