[u/mrichter/AliRoot.git] / HIJING / hijing1_36 / gauss3.F

* $Id$
C
C
C
	FUNCTION GAUSS3(F,A,B,EPS)
	EXTERNAL F
	DIMENSION W(12),X(12)
	DATA CONST/1.0E-12/
	DATA W/0.1012285,.2223810,.3137067,.3623838,.0271525,
     &         .0622535,0.0951585,.1246290,.1495960,.1691565,
     &         .1826034,.1894506/
	DATA X/0.9602899,.7966665,.5255324,.1834346,.9894009,
     &         .9445750,0.8656312,.7554044,.6178762,.4580168,
     &         .2816036,.0950125/
	SAVE
	DELTA=CONST*ABS(A-B)
	GAUSS3=0.0
	AA=A
5	Y=B-AA
	IF(ABS(Y).LE.DELTA) RETURN
2	BB=AA+Y
	C1=0.5*(AA+BB)
	C2=C1-AA
	S8=0.0
	S16=0.0
	DO 1 I=1,4
	U=X(I)*C2
1	S8=S8+W(I)*(F(C1+U)+F(C1-U))
	DO 3 I=5,12
	U=X(I)*C2
3	S16=S16+W(I)*(F(C1+U)+F(C1-U))
	S8=S8*C2
	S16=S16*C2
	IF(ABS(S16-S8).GT.EPS*(1.+ABS(S16))) GOTO 4
	GAUSS3=GAUSS3+S16
	AA=BB
	GOTO 5
4	Y=0.5*Y
	IF(ABS(Y).GT.DELTA) GOTO 2
	WRITE(6,7)
	GAUSS3=0.0
	RETURN
7	FORMAT(1X,'GAUSS3....TOO HIGH ACURACY REQUIRED')
	END
Commit	Line	Data
e74335a4	1	* $Id$
	2	C
	3	C
	4	C
	5	FUNCTION GAUSS3(F,A,B,EPS)
	6	EXTERNAL F
	7	DIMENSION W(12),X(12)
	8	DATA CONST/1.0E-12/
	9	DATA W/0.1012285,.2223810,.3137067,.3623838,.0271525,
	10	& .0622535,0.0951585,.1246290,.1495960,.1691565,
	11	& .1826034,.1894506/
	12	DATA X/0.9602899,.7966665,.5255324,.1834346,.9894009,
	13	& .9445750,0.8656312,.7554044,.6178762,.4580168,
	14	& .2816036,.0950125/
	15	SAVE
	16	DELTA=CONST*ABS(A-B)
	17	GAUSS3=0.0
	18	AA=A
	19	5 Y=B-AA
	20	IF(ABS(Y).LE.DELTA) RETURN
	21	2 BB=AA+Y
	22	C1=0.5*(AA+BB)
	23	C2=C1-AA
	24	S8=0.0
	25	S16=0.0
	26	DO 1 I=1,4
	27	U=X(I)*C2
	28	1 S8=S8+W(I)*(F(C1+U)+F(C1-U))
	29	DO 3 I=5,12
	30	U=X(I)*C2
	31	3 S16=S16+W(I)*(F(C1+U)+F(C1-U))
	32	S8=S8*C2
	33	S16=S16*C2
	34	IF(ABS(S16-S8).GT.EPS*(1.+ABS(S16))) GOTO 4
	35	GAUSS3=GAUSS3+S16
	36	AA=BB
	37	GOTO 5
	38	4 Y=0.5*Y
	39	IF(ABS(Y).GT.DELTA) GOTO 2
	40	WRITE(6,7)
	41	GAUSS3=0.0
	42	RETURN
	43	7 FORMAT(1X,'GAUSS3....TOO HIGH ACURACY REQUIRED')
	44	END