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
|
double precision function round(x1)
c!
c Copyright INRIA
double precision x1,x,y,z,e,h
data h/1.0d+9/
c
x=x1
if (x.eq.0d0) then
round=x
return
endif
if ((2.0d0*x).eq.dble(int(2.d0*x))) then
c for compatibily with others change the two signs below
c -----we assume round(0.5)=0 round(-0.5)=0------------
c changing the signs gives round(0.5)=1 and round(-0.5)=-1
if (x.gt.0.d0) x=x-1.d-10
if (x.lt.0.d0) x=x+1.d-10
endif
z = abs(x)
c -----testing Nans
if (isanan(x).eq.1) then
round=x
return
endif
y = z + 1.0d+0
if (y .eq. z) then
round=x
return
endif
y = 0.0d+0
e = h
10 if (e .ge. z) go to 20
e = 2.0d+0*e
go to 10
20 if (e .le. h) go to 30
if (e .le. z) y = y + e
if (e .le. z) z = z - e
e = e/2.0d+0
go to 20
30 z = int(z + 0.50d+0)
y = y + z
if (x .lt. 0.0d+0) y = -y
round = y
return
end
|
