1 |
guez |
131 |
module invert_zoom_x_m |
2 |
guez |
121 |
|
3 |
|
|
implicit none |
4 |
|
|
|
5 |
|
|
INTEGER, PARAMETER:: nmax = 30000 |
6 |
|
|
|
7 |
|
|
contains |
8 |
|
|
|
9 |
guez |
131 |
subroutine invert_zoom_x(xf, xtild, Xprimt, xlon, xprimm, xuv) |
10 |
guez |
121 |
|
11 |
|
|
use coefpoly_m, only: coefpoly |
12 |
|
|
USE dimens_m, ONLY: iim |
13 |
guez |
139 |
use dynetat0_m, only: clon |
14 |
guez |
124 |
use nr_util, only: pi_d, twopi_d |
15 |
guez |
145 |
use numer_rec_95, only: hunt |
16 |
guez |
121 |
|
17 |
|
|
DOUBLE PRECISION, intent(in):: Xf(0:), xtild(0:), Xprimt(0:) ! (0:2 * nmax) |
18 |
guez |
124 |
real, intent(out):: xlon(:), xprimm(:) ! (iim) |
19 |
guez |
121 |
|
20 |
|
|
DOUBLE PRECISION, intent(in):: xuv |
21 |
guez |
145 |
! between - 0.25 and 0.5 |
22 |
guez |
121 |
! 0. si calcul aux points scalaires |
23 |
guez |
145 |
! 0.5 si calcul aux points U |
24 |
guez |
121 |
|
25 |
|
|
! Local: |
26 |
guez |
126 |
DOUBLE PRECISION xo1, Xfi, a0, a1, a2, a3, Xf1, Xprimin |
27 |
|
|
integer i, it, iter |
28 |
|
|
DOUBLE PRECISION, parameter:: my_eps = 1d-6 |
29 |
guez |
121 |
|
30 |
guez |
126 |
DOUBLE PRECISION xxprim(iim), xvrai(iim) |
31 |
|
|
! intermediary variables because xlon and xprimm are simple precision |
32 |
|
|
|
33 |
guez |
121 |
!------------------------------------------------------------------ |
34 |
|
|
|
35 |
guez |
145 |
it = 0 ! initial guess |
36 |
|
|
|
37 |
guez |
126 |
DO i = 1, iim |
38 |
|
|
Xfi = - pi_d + (i + xuv - 0.75d0) * twopi_d / iim |
39 |
guez |
145 |
! - pi <= xfi < pi |
40 |
guez |
121 |
|
41 |
guez |
145 |
call hunt(xf, xfi, it, my_lbound = 0) |
42 |
|
|
it = max(0, it) |
43 |
|
|
! In principle, xfi >= xf(0), max with 0 just in case of |
44 |
|
|
! roundoff error. {0 <= it <= 2 * nmax - 1} |
45 |
guez |
121 |
|
46 |
guez |
126 |
! Calcul de Xf(xvrai(i)) |
47 |
guez |
121 |
|
48 |
|
|
CALL coefpoly(Xf(it), Xf(it + 1), Xprimt(it), Xprimt(it + 1), & |
49 |
|
|
xtild(it), xtild(it + 1), a0, a1, a2, a3) |
50 |
guez |
145 |
xvrai(i) = xtild(it) |
51 |
guez |
121 |
Xf1 = Xf(it) |
52 |
guez |
126 |
Xprimin = a1 + xvrai(i) * (2d0 * a2 + xvrai(i) * 3d0 * a3) |
53 |
|
|
xo1 = xvrai(i) |
54 |
guez |
121 |
iter = 1 |
55 |
|
|
|
56 |
|
|
do |
57 |
guez |
126 |
xvrai(i) = xvrai(i) - (Xf1 - Xfi) / Xprimin |
58 |
|
|
IF (ABS(xvrai(i) - xo1) <= my_eps .or. iter == 300) exit |
59 |
|
|
xo1 = xvrai(i) |
60 |
|
|
Xf1 = a0 + xvrai(i) * (a1 + xvrai(i) * (a2 + xvrai(i) * a3)) |
61 |
|
|
Xprimin = a1 + xvrai(i) * (2d0 * a2 + xvrai(i) * 3d0 * a3) |
62 |
guez |
121 |
end DO |
63 |
|
|
|
64 |
guez |
126 |
if (ABS(xvrai(i) - xo1) > my_eps) then |
65 |
guez |
121 |
! iter == 300 |
66 |
|
|
print *, 'Pas de solution.' |
67 |
|
|
print *, i, xfi |
68 |
|
|
STOP 1 |
69 |
|
|
end if |
70 |
|
|
|
71 |
guez |
126 |
xxprim(i) = twopi_d / (iim * Xprimin) |
72 |
guez |
121 |
end DO |
73 |
|
|
|
74 |
|
|
DO i = 1, iim -1 |
75 |
|
|
IF (xvrai(i + 1) < xvrai(i)) THEN |
76 |
guez |
124 |
print *, 'xvrai(', i + 1, ') < xvrai(', i, ')' |
77 |
guez |
121 |
STOP 1 |
78 |
|
|
END IF |
79 |
|
|
END DO |
80 |
|
|
|
81 |
guez |
127 |
xlon = xvrai + clon |
82 |
guez |
126 |
xprimm = xxprim |
83 |
guez |
121 |
|
84 |
guez |
131 |
end subroutine invert_zoom_x |
85 |
guez |
121 |
|
86 |
guez |
131 |
end module invert_zoom_x_m |