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Contents of /trunk/Sources/dyn3d/fxhyp.f

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Revision 148 - (show annotations)
Wed Jun 17 16:40:24 2015 UTC (8 years, 10 months ago) by guez
File size: 5004 byte(s)
Renamed variables in fxhyp and invert_zoom_x to be closer to external
documentation. Changed from double precision to real in invert_zoom_x:
I do not see the need for double precision and double precision is
annoying because I want to use rtsafe without overloading it in
Numer_Rec_95.

Results are changed at the numerical noise level.

1 module fxhyp_m
2
3 IMPLICIT NONE
4
5 contains
6
7 SUBROUTINE fxhyp(xprimm025, rlonv, xprimv, rlonu, xprimu, xprimp025)
8
9 ! From LMDZ4/libf/dyn3d/fxhyp.F, version 1.2, 2005/06/03 09:11:32
10 ! Author: P. Le Van, from formulas by R. Sadourny
11
12 ! Calcule les longitudes et dérivées dans la grille du GCM pour
13 ! une fonction f(x) à dérivée tangente hyperbolique.
14
15 ! Il vaut mieux avoir : grossismx \times delta < pi
16
17 ! Le premier point scalaire pour une grille regulière (grossismx =
18 ! 1., taux = 0., clon = 0.) est à - 180 degrés.
19
20 USE dimens_m, ONLY: iim
21 use dynetat0_m, only: clon, grossismx, dzoomx, taux
22 use invert_zoom_x_m, only: invert_zoom_x, nmax
23 use nr_util, only: pi, pi_d, twopi, twopi_d, arth
24 use principal_cshift_m, only: principal_cshift
25 use tanh_cautious_m, only: tanh_cautious
26
27 REAL, intent(out):: xprimm025(:), rlonv(:), xprimv(:) ! (iim + 1)
28 real, intent(out):: rlonu(:), xprimu(:), xprimp025(:) ! (iim + 1)
29
30 ! Local:
31 real rlonm025(iim + 1), rlonp025(iim + 1), d_rlonv(iim)
32 REAL delta, step
33 DOUBLE PRECISION, dimension(0:nmax):: xtild, fhyp, G, Xf, ffdx
34 DOUBLE PRECISION beta
35 INTEGER i, is2
36 DOUBLE PRECISION xmoy(nmax), fxm(nmax)
37
38 !----------------------------------------------------------------------
39
40 print *, "Call sequence information: fxhyp"
41
42 if (grossismx == 1.) then
43 step = twopi / iim
44
45 xprimm025(:iim) = step
46 xprimp025(:iim) = step
47 xprimv(:iim) = step
48 xprimu(:iim) = step
49
50 rlonv(:iim) = arth(- pi + clon, step, iim)
51 rlonm025(:iim) = rlonv(:iim) - 0.25 * step
52 rlonp025(:iim) = rlonv(:iim) + 0.25 * step
53 rlonu(:iim) = rlonv(:iim) + 0.5 * step
54 else
55 delta = dzoomx * twopi_d
56 xtild = arth(0d0, pi_d / nmax, nmax + 1)
57 forall (i = 1:nmax) xmoy(i) = 0.5d0 * (xtild(i-1) + xtild(i))
58
59 ! Compute fhyp:
60 fhyp(1:nmax - 1) = tanh_cautious(taux * (delta / 2d0 &
61 - xtild(1:nmax - 1)), xtild(1:nmax - 1) &
62 * (pi_d - xtild(1:nmax - 1)))
63 fhyp(0) = 1d0
64 fhyp(nmax) = -1d0
65
66 fxm = tanh_cautious(taux * (delta / 2d0 - xmoy), xmoy * (pi_d - xmoy))
67
68 ! Compute \int_0 ^{\tilde x} F:
69
70 ffdx(0) = 0d0
71
72 DO i = 1, nmax
73 ffdx(i) = ffdx(i - 1) + fxm(i) * (xtild(i) - xtild(i-1))
74 END DO
75
76 print *, "ffdx(nmax) = ", ffdx(nmax)
77 beta = (pi_d - grossismx * ffdx(nmax)) / (pi_d - ffdx(nmax))
78 print *, "beta = ", beta
79
80 IF (2d0 * beta - grossismx <= 0d0) THEN
81 print *, 'Bad choice of grossismx, taux, dzoomx.'
82 print *, 'Decrease dzoomx or grossismx.'
83 STOP 1
84 END IF
85
86 G = beta + (grossismx - beta) * fhyp
87
88 Xf(:nmax - 1) = beta * xtild(:nmax - 1) + (grossismx - beta) &
89 * ffdx(:nmax - 1)
90 Xf(nmax) = pi_d
91
92 call invert_zoom_x(xf, xtild, G, rlonm025(:iim), xprimm025(:iim), &
93 xuv = - 0.25d0)
94 call invert_zoom_x(xf, xtild, G, rlonv(:iim), xprimv(:iim), xuv = 0d0)
95 call invert_zoom_x(xf, xtild, G, rlonu(:iim), xprimu(:iim), xuv = 0.5d0)
96 call invert_zoom_x(xf, xtild, G, rlonp025(:iim), xprimp025(:iim), &
97 xuv = 0.25d0)
98 end if
99
100 is2 = 0
101
102 IF (MINval(rlonm025(:iim)) < - pi - 0.1 &
103 .or. MAXval(rlonm025(:iim)) > pi + 0.1) THEN
104 IF (clon <= 0.) THEN
105 is2 = 1
106
107 do while (rlonm025(is2) < - pi .and. is2 < iim)
108 is2 = is2 + 1
109 end do
110
111 if (rlonm025(is2) < - pi) then
112 print *, 'Rlonm025 plus petit que - pi !'
113 STOP 1
114 end if
115 ELSE
116 is2 = iim
117
118 do while (rlonm025(is2) > pi .and. is2 > 1)
119 is2 = is2 - 1
120 end do
121
122 if (rlonm025(is2) > pi) then
123 print *, 'Rlonm025 plus grand que pi !'
124 STOP 1
125 end if
126 END IF
127 END IF
128
129 call principal_cshift(is2, rlonm025, xprimm025)
130 call principal_cshift(is2, rlonv, xprimv)
131 call principal_cshift(is2, rlonu, xprimu)
132 call principal_cshift(is2, rlonp025, xprimp025)
133
134 forall (i = 1: iim) d_rlonv(i) = rlonv(i + 1) - rlonv(i)
135 print *, "Minimum longitude step:", MINval(d_rlonv) * 180. / pi, "degrees"
136 print *, "Maximum longitude step:", MAXval(d_rlonv) * 180. / pi, "degrees"
137
138 ! Check that rlonm025 <= rlonv <= rlonp025 <= rlonu:
139 DO i = 1, iim + 1
140 IF (rlonp025(i) < rlonv(i)) THEN
141 print *, 'rlonp025(', i, ') = ', rlonp025(i)
142 print *, "< rlonv(", i, ") = ", rlonv(i)
143 STOP 1
144 END IF
145
146 IF (rlonv(i) < rlonm025(i)) THEN
147 print *, 'rlonv(', i, ') = ', rlonv(i)
148 print *, "< rlonm025(", i, ") = ", rlonm025(i)
149 STOP 1
150 END IF
151
152 IF (rlonp025(i) > rlonu(i)) THEN
153 print *, 'rlonp025(', i, ') = ', rlonp025(i)
154 print *, "> rlonu(", i, ") = ", rlonu(i)
155 STOP 1
156 END IF
157 END DO
158
159 END SUBROUTINE fxhyp
160
161 end module fxhyp_m

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