1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
|
SUBROUTINE cumchi(x,df,cum,ccum)
C**********************************************************************
C
C SUBROUTINE FUNCTION CUMCHI(X,DF,CUM,CCUM)
C CUMulative of the CHi-square distribution
C
C
C Function
C
C
C Calculates the cumulative chi-square distribution.
C
C
C Arguments
C
C
C X --> Upper limit of integration of the
C chi-square distribution.
C X is DOUBLE PRECISION
C
C DF --> Degrees of freedom of the
C chi-square distribution.
C DF is DOUBLE PRECISION
C
C CUM <-- Cumulative chi-square distribution.
C CUM is DOUBLE PRECISIO
C
C CCUM <-- Compliment of Cumulative chi-square distribution.
C CCUM is DOUBLE PRECISI
C
C
C Method
C
C
C Calls incomplete gamma function (CUMGAM)
C
C**********************************************************************
C .. Scalar Arguments ..
DOUBLE PRECISION df,x,cum,ccum
C ..
C .. Local Scalars ..
DOUBLE PRECISION a,xx
C ..
C .. External Subroutines ..
EXTERNAL cumgam
C ..
C .. Executable Statements ..
a = df*0.5D0
xx = x*0.5D0
CALL cumgam(xx,a,cum,ccum)
RETURN
END
|
