1 | ! $Id: disvert.F90 4368 2022-12-05 23:01:16Z aborella $ |
---|
2 | |
---|
3 | SUBROUTINE disvert() |
---|
4 | |
---|
5 | #ifdef CPP_IOIPSL |
---|
6 | use ioipsl, only: getin |
---|
7 | #else |
---|
8 | USE ioipsl_getincom, only: getin |
---|
9 | #endif |
---|
10 | use new_unit_m, only: new_unit |
---|
11 | use assert_m, only: assert |
---|
12 | USE comvert_mod, ONLY: ap, bp, aps, bps, nivsigs, nivsig, dpres, presnivs, & |
---|
13 | pseudoalt, pa, preff, scaleheight, presinter |
---|
14 | USE logic_mod, ONLY: ok_strato |
---|
15 | |
---|
16 | IMPLICIT NONE |
---|
17 | |
---|
18 | include "dimensions.h" |
---|
19 | include "paramet.h" |
---|
20 | include "iniprint.h" |
---|
21 | |
---|
22 | !------------------------------------------------------------------------------- |
---|
23 | ! Purpose: Vertical distribution functions for LMDZ. |
---|
24 | ! Triggered by the levels number llm. |
---|
25 | !------------------------------------------------------------------------------- |
---|
26 | ! Read in "comvert_mod": |
---|
27 | |
---|
28 | ! pa !--- vertical coordinate is close to a PRESSURE COORDINATE FOR P |
---|
29 | ! < 0.3 * pa (relative variation of p on a model level is < 0.1 %) |
---|
30 | |
---|
31 | ! preff !--- REFERENCE PRESSURE (101325 Pa) |
---|
32 | ! Written in "comvert_mod": |
---|
33 | ! ap(llm+1), bp(llm+1) !--- Ap, Bp HYBRID COEFFICIENTS AT INTERFACES |
---|
34 | ! aps(llm), bps(llm) !--- Ap, Bp HYBRID COEFFICIENTS AT MID-LAYERS |
---|
35 | ! dpres(llm) !--- PRESSURE DIFFERENCE FOR EACH LAYER |
---|
36 | ! presnivs(llm) !--- PRESSURE AT EACH MID-LAYER |
---|
37 | ! presinter(llm+1) !--- PRESSURE AT EACH INTERFACE |
---|
38 | ! scaleheight !--- VERTICAL SCALE HEIGHT (Earth: 8kms) |
---|
39 | ! nivsig(llm+1) !--- SIGMA INDEX OF EACH LAYER INTERFACE |
---|
40 | ! nivsigs(llm) !--- SIGMA INDEX OF EACH MID-LAYER |
---|
41 | !------------------------------------------------------------------------------- |
---|
42 | ! Local variables: |
---|
43 | REAL sig(llm+1), dsig(llm) |
---|
44 | REAL sig0(llm+1), zz(llm+1) |
---|
45 | REAL zk, zkm1, dzk1, dzk2, z, k0, k1 |
---|
46 | |
---|
47 | INTEGER l, unit |
---|
48 | REAL dsigmin |
---|
49 | REAL vert_scale,vert_dzmin,vert_dzlow,vert_z0low,vert_dzmid,vert_z0mid,vert_h_mid,vert_dzhig,vert_z0hig,vert_h_hig |
---|
50 | |
---|
51 | REAL alpha, beta, deltaz |
---|
52 | REAL x |
---|
53 | character(len=*),parameter :: modname="disvert" |
---|
54 | |
---|
55 | character(len=24):: vert_sampling |
---|
56 | ! (allowed values are "param", "tropo", "strato" and "read") |
---|
57 | |
---|
58 | !----------------------------------------------------------------------- |
---|
59 | |
---|
60 | WRITE(lunout,*) TRIM(modname)//" starts" |
---|
61 | |
---|
62 | ! default scaleheight is 8km for earth |
---|
63 | scaleheight=8. |
---|
64 | |
---|
65 | vert_sampling = merge("strato", "tropo ", ok_strato) ! default value |
---|
66 | call getin('vert_sampling', vert_sampling) |
---|
67 | WRITE(lunout,*) TRIM(modname)//' vert_sampling = ' // vert_sampling |
---|
68 | if (llm==39 .and. vert_sampling=="strato") then |
---|
69 | dsigmin=0.3 ! Vieille option par défaut pour CMIP5 |
---|
70 | else |
---|
71 | dsigmin=1. |
---|
72 | endif |
---|
73 | call getin('dsigmin', dsigmin) |
---|
74 | WRITE(LUNOUT,*) trim(modname), 'Discretisation verticale DSIGMIN=',dsigmin |
---|
75 | |
---|
76 | |
---|
77 | select case (vert_sampling) |
---|
78 | case ("param") |
---|
79 | ! On lit les options dans sigma.def: |
---|
80 | OPEN(99, file='sigma.def', status='old', form='formatted') |
---|
81 | READ(99, *) scaleheight ! hauteur d'echelle 8. |
---|
82 | READ(99, *) deltaz ! epaiseur de la premiere couche 0.04 |
---|
83 | READ(99, *) beta ! facteur d'acroissement en haut 1.3 |
---|
84 | READ(99, *) k0 ! nombre de couches dans la transition surf |
---|
85 | READ(99, *) k1 ! nombre de couches dans la transition haute |
---|
86 | CLOSE(99) |
---|
87 | alpha=deltaz/(llm*scaleheight) |
---|
88 | write(lunout, *)trim(modname),':scaleheight, alpha, k0, k1, beta', & |
---|
89 | scaleheight, alpha, k0, k1, beta |
---|
90 | |
---|
91 | alpha=deltaz/tanh(1./k0)*2. |
---|
92 | zkm1=0. |
---|
93 | sig(1)=1. |
---|
94 | do l=1, llm |
---|
95 | sig(l+1)=(cosh(l/k0))**(-alpha*k0/scaleheight) & |
---|
96 | *exp(-alpha/scaleheight*tanh((llm-k1)/k0) & |
---|
97 | *beta**(l-(llm-k1))/log(beta)) |
---|
98 | zk=-scaleheight*log(sig(l+1)) |
---|
99 | |
---|
100 | dzk1=alpha*tanh(l/k0) |
---|
101 | dzk2=alpha*tanh((llm-k1)/k0)*beta**(l-(llm-k1))/log(beta) |
---|
102 | write(lunout, *)l, sig(l+1), zk, zk-zkm1, dzk1, dzk2 |
---|
103 | zkm1=zk |
---|
104 | enddo |
---|
105 | |
---|
106 | sig(llm+1)=0. |
---|
107 | |
---|
108 | bp(: llm) = EXP(1. - 1. / sig(: llm)**2) |
---|
109 | bp(llmp1) = 0. |
---|
110 | |
---|
111 | ap = pa * (sig - bp) |
---|
112 | case("sigma") |
---|
113 | DO l = 1, llm |
---|
114 | x = 2*asin(1.) * (l - 0.5) / (llm + 1) |
---|
115 | dsig(l) = dsigmin + 7.0 * SIN(x)**2 |
---|
116 | ENDDO |
---|
117 | dsig = dsig / sum(dsig) |
---|
118 | sig(llm+1) = 0. |
---|
119 | DO l = llm, 1, -1 |
---|
120 | sig(l) = sig(l+1) + dsig(l) |
---|
121 | ENDDO |
---|
122 | |
---|
123 | bp(1)=1. |
---|
124 | bp(2: llm) = sig(2:llm) |
---|
125 | bp(llmp1) = 0. |
---|
126 | ap(:)=0. |
---|
127 | case("tropo") |
---|
128 | DO l = 1, llm |
---|
129 | x = 2*asin(1.) * (l - 0.5) / (llm + 1) |
---|
130 | dsig(l) = dsigmin + 7.0 * SIN(x)**2 |
---|
131 | ENDDO |
---|
132 | dsig = dsig / sum(dsig) |
---|
133 | sig(llm+1) = 0. |
---|
134 | DO l = llm, 1, -1 |
---|
135 | sig(l) = sig(l+1) + dsig(l) |
---|
136 | ENDDO |
---|
137 | |
---|
138 | bp(1)=1. |
---|
139 | bp(2: llm) = EXP(1. - 1. / sig(2: llm)**2) |
---|
140 | bp(llmp1) = 0. |
---|
141 | |
---|
142 | ap(1)=0. |
---|
143 | ap(2: llm + 1) = pa * (sig(2: llm + 1) - bp(2: llm + 1)) |
---|
144 | case("strato") |
---|
145 | DO l = 1, llm |
---|
146 | x = 2*asin(1.) * (l - 0.5) / (llm + 1) |
---|
147 | dsig(l) =(dsigmin + 7. * SIN(x)**2) & |
---|
148 | *(0.5*(1.-tanh(1.*(x-asin(1.))/asin(1.))))**2 |
---|
149 | ENDDO |
---|
150 | dsig = dsig / sum(dsig) |
---|
151 | sig(llm+1) = 0. |
---|
152 | DO l = llm, 1, -1 |
---|
153 | sig(l) = sig(l+1) + dsig(l) |
---|
154 | ENDDO |
---|
155 | |
---|
156 | bp(1)=1. |
---|
157 | bp(2: llm) = EXP(1. - 1. / sig(2: llm)**2) |
---|
158 | bp(llmp1) = 0. |
---|
159 | |
---|
160 | ap(1)=0. |
---|
161 | ap(2: llm + 1) = pa * (sig(2: llm + 1) - bp(2: llm + 1)) |
---|
162 | case("strato_correct") |
---|
163 | !================================================================== |
---|
164 | ! Fredho 2014/05/18, Saint-Louis du Senegal |
---|
165 | ! Cette version de la discretisation strato est corrige au niveau |
---|
166 | ! du passage des sig aux ap, bp |
---|
167 | ! la version precedente donne un coude dans l'epaisseur des couches |
---|
168 | ! vers la tropopause |
---|
169 | !================================================================== |
---|
170 | |
---|
171 | |
---|
172 | DO l = 1, llm |
---|
173 | x = 2*asin(1.) * (l - 0.5) / (llm + 1) |
---|
174 | dsig(l) =(dsigmin + 7. * SIN(x)**2) & |
---|
175 | *(0.5*(1.-tanh(1.*(x-asin(1.))/asin(1.))))**2 |
---|
176 | ENDDO |
---|
177 | dsig = dsig / sum(dsig) |
---|
178 | sig0(llm+1) = 0. |
---|
179 | DO l = llm, 1, -1 |
---|
180 | sig0(l) = sig0(l+1) + dsig(l) |
---|
181 | ENDDO |
---|
182 | sig=racinesig(sig0) |
---|
183 | |
---|
184 | bp(1)=1. |
---|
185 | bp(2:llm)=EXP(1.-1./sig(2: llm)**2) |
---|
186 | bp(llmp1)=0. |
---|
187 | |
---|
188 | ap(1)=0. |
---|
189 | ap(2:llm)=pa*(sig(2:llm)-bp(2:llm)) |
---|
190 | ap(llm+1)=0. |
---|
191 | |
---|
192 | CASE("strato_custom0") |
---|
193 | !======================================================= |
---|
194 | ! Version Transitoire |
---|
195 | ! custumize strato distribution with specific alpha & beta values and function |
---|
196 | ! depending on llm (experimental and temporary)! |
---|
197 | SELECT CASE (llm) |
---|
198 | CASE(55) |
---|
199 | alpha=0.45 |
---|
200 | beta=4.0 |
---|
201 | CASE(63) |
---|
202 | alpha=0.45 |
---|
203 | beta=5.0 |
---|
204 | CASE(71) |
---|
205 | alpha=3.05 |
---|
206 | beta=65. |
---|
207 | CASE(79) |
---|
208 | alpha=3.20 |
---|
209 | ! alpha=2.05 ! FLOTT 79 (PLANTE) |
---|
210 | beta=70. |
---|
211 | END SELECT |
---|
212 | ! Or used values provided by user in def file: |
---|
213 | CALL getin("strato_alpha",alpha) |
---|
214 | CALL getin("strato_beta",beta) |
---|
215 | |
---|
216 | ! Build geometrical distribution |
---|
217 | scaleheight=7. |
---|
218 | zz(1)=0. |
---|
219 | IF (llm==55.OR.llm==63) THEN |
---|
220 | DO l=1,llm |
---|
221 | z=zz(l)/scaleheight |
---|
222 | zz(l+1)=zz(l)+0.03+z*1.5*(1.-TANH(z-0.5))+alpha*(1.+TANH(z-1.5)) & |
---|
223 | +5.0*EXP((l-llm)/beta) |
---|
224 | ENDDO |
---|
225 | ELSEIF (llm==71) THEN !.OR.llm==79) THEN ! FLOTT 79 (PLANTE) |
---|
226 | DO l=1,llm |
---|
227 | z=zz(l) |
---|
228 | zz(l+1)=zz(l)+0.02+0.88*TANH(z/2.5)+alpha*(1.+TANH((z-beta)/15.)) |
---|
229 | ENDDO |
---|
230 | ELSEIF (llm==79) THEN |
---|
231 | DO l=1,llm |
---|
232 | z=zz(l) |
---|
233 | zz(l+1)=zz(l)+0.02+0.80*TANH(z/3.8)+alpha*(1+TANH((z-beta)/17.)) & |
---|
234 | +0.03*TANH(z/.25) |
---|
235 | ENDDO |
---|
236 | ENDIF ! of IF (llm==55.OR.llm==63) ... |
---|
237 | |
---|
238 | |
---|
239 | ! Build sigma distribution |
---|
240 | sig0=EXP(-zz(:)/scaleheight) |
---|
241 | sig0(llm+1)=0. |
---|
242 | ! sig=ridders(sig0) |
---|
243 | sig=racinesig(sig0) |
---|
244 | |
---|
245 | ! Compute ap() and bp() |
---|
246 | bp(1)=1. |
---|
247 | bp(2:llm)=EXP(1.-1./sig(2:llm)**2) |
---|
248 | bp(llm+1)=0. |
---|
249 | ap=pa*(sig-bp) |
---|
250 | |
---|
251 | CASE("strato_custom") |
---|
252 | !=================================================================== |
---|
253 | ! David Cugnet, François Lott, Lionel Guez, Ehouoarn Millour, Fredho |
---|
254 | ! 2014/05 |
---|
255 | ! custumize strato distribution |
---|
256 | ! Al the parameter are given in km assuming a given scalehigh |
---|
257 | vert_scale=7. ! scale hight |
---|
258 | vert_dzmin=0.02 ! width of first layer |
---|
259 | vert_dzlow=1. ! dz in the low atmosphere |
---|
260 | vert_z0low=8. ! height at which resolution recches dzlow |
---|
261 | vert_dzmid=3. ! dz in the mid atmsophere |
---|
262 | vert_z0mid=70. ! height at which resolution recches dzmid |
---|
263 | vert_h_mid=20. ! width of the transition |
---|
264 | vert_dzhig=11. ! dz in the high atmsophere |
---|
265 | vert_z0hig=80. ! height at which resolution recches dz |
---|
266 | vert_h_hig=20. ! width of the transition |
---|
267 | !=================================================================== |
---|
268 | |
---|
269 | call getin('vert_scale',vert_scale) |
---|
270 | call getin('vert_dzmin',vert_dzmin) |
---|
271 | call getin('vert_dzlow',vert_dzlow) |
---|
272 | call getin('vert_z0low',vert_z0low) |
---|
273 | CALL getin('vert_dzmid',vert_dzmid) |
---|
274 | CALL getin('vert_z0mid',vert_z0mid) |
---|
275 | call getin('vert_h_mid',vert_h_mid) |
---|
276 | call getin('vert_dzhig',vert_dzhig) |
---|
277 | call getin('vert_z0hig',vert_z0hig) |
---|
278 | call getin('vert_h_hig',vert_h_hig) |
---|
279 | |
---|
280 | scaleheight=vert_scale ! for consistency with further computations |
---|
281 | ! Build geometrical distribution |
---|
282 | zz(1)=0. |
---|
283 | DO l=1,llm |
---|
284 | z=zz(l) |
---|
285 | zz(l+1)=zz(l)+vert_dzmin+vert_dzlow*TANH(z/vert_z0low)+ & |
---|
286 | & (vert_dzmid-vert_dzlow)* & |
---|
287 | & (TANH((z-vert_z0mid)/vert_h_mid)-TANH((-vert_z0mid)/vert_h_mid)) & |
---|
288 | & +(vert_dzhig-vert_dzmid-vert_dzlow)* & |
---|
289 | & (TANH((z-vert_z0hig)/vert_h_hig)-TANH((-vert_z0hig)/vert_h_hig)) |
---|
290 | ENDDO |
---|
291 | |
---|
292 | |
---|
293 | !=================================================================== |
---|
294 | ! Comment added Fredho 2014/05/18, Saint-Louis, Senegal |
---|
295 | ! From approximate z to ap, bp, so that p=ap+bp*p0 and p/p0=exp(-z/H) |
---|
296 | ! sig0 is p/p0 |
---|
297 | ! sig is an intermediate distribution introduce to estimate bp |
---|
298 | ! 1. sig0=exp(-z/H) |
---|
299 | ! 2. inversion of sig0=(1-pa/p0)*sig+(1-pa/p0)*exp(1-1/sig**2) |
---|
300 | ! 3. bp=exp(1-1/sig**2) |
---|
301 | ! 4. ap deduced from the combination of 2 and 3 so that sig0=ap/p0+bp |
---|
302 | !=================================================================== |
---|
303 | |
---|
304 | sig0=EXP(-zz(:)/vert_scale) |
---|
305 | sig0(llm+1)=0. |
---|
306 | sig=racinesig(sig0) |
---|
307 | bp(1)=1. |
---|
308 | bp(2:llm)=EXP(1.-1./sig(2:llm)**2) |
---|
309 | bp(llm+1)=0. |
---|
310 | ap=pa*(sig-bp) |
---|
311 | |
---|
312 | case("read") |
---|
313 | ! Read "ap" and "bp". First line is skipped (title line). "ap" |
---|
314 | ! should be in Pa. First couple of values should correspond to |
---|
315 | ! the surface, that is : "bp" should be in descending order. |
---|
316 | call new_unit(unit) |
---|
317 | open(unit, file="hybrid.txt", status="old", action="read", & |
---|
318 | position="rewind") |
---|
319 | read(unit, fmt=*) ! skip title line |
---|
320 | do l = 1, llm + 1 |
---|
321 | read(unit, fmt=*) ap(l), bp(l) |
---|
322 | end do |
---|
323 | close(unit) |
---|
324 | call assert(ap(1) == 0., ap(llm + 1) == 0., bp(1) == 1., & |
---|
325 | bp(llm + 1) == 0., "disvert: bad ap or bp values") |
---|
326 | case default |
---|
327 | call abort_gcm("disvert", 'Wrong value for "vert_sampling"', 1) |
---|
328 | END select |
---|
329 | |
---|
330 | DO l=1, llm |
---|
331 | nivsigs(l) = REAL(l) |
---|
332 | ENDDO |
---|
333 | |
---|
334 | DO l=1, llmp1 |
---|
335 | nivsig(l)= REAL(l) |
---|
336 | ENDDO |
---|
337 | |
---|
338 | write(lunout, *) trim(modname),': BP ' |
---|
339 | write(lunout, *) bp |
---|
340 | write(lunout, *) trim(modname),': AP ' |
---|
341 | write(lunout, *) ap |
---|
342 | |
---|
343 | write(lunout, *) 'Niveaux de pressions approximatifs aux centres des' |
---|
344 | write(lunout, *)'couches calcules pour une pression de surface =', preff |
---|
345 | write(lunout, *) 'et altitudes equivalentes pour une hauteur d echelle de ' |
---|
346 | write(lunout, *) scaleheight,' km' |
---|
347 | DO l = 1, llm |
---|
348 | dpres(l) = bp(l) - bp(l+1) |
---|
349 | aps(l) = 0.5 *( ap(l) +ap(l+1)) |
---|
350 | bps(l) = 0.5 *( bp(l) +bp(l+1)) |
---|
351 | presnivs(l) = 0.5 *( ap(l)+bp(l)*preff + ap(l+1)+bp(l+1)*preff ) |
---|
352 | pseudoalt(l) = log(preff/presnivs(l))*scaleheight |
---|
353 | write(lunout, *)'PRESNIVS(', l, ')=', presnivs(l), ' Z ~ ', & |
---|
354 | pseudoalt(l) & |
---|
355 | , ' DZ ~ ', scaleheight*log((ap(l)+bp(l)*preff)/ & |
---|
356 | max(ap(l+1)+bp(l+1)*preff, 1.e-10)) |
---|
357 | ENDDO |
---|
358 | DO l=1, llmp1 |
---|
359 | presinter(l)= ( ap(l)+bp(l)*preff) |
---|
360 | write(lunout, *)'PRESINTER(', l, ')=', presinter(l) |
---|
361 | ENDDO |
---|
362 | |
---|
363 | write(lunout, *) trim(modname),': PRESNIVS ' |
---|
364 | write(lunout, *) presnivs |
---|
365 | |
---|
366 | CONTAINS |
---|
367 | |
---|
368 | !------------------------------------------------------------------------------- |
---|
369 | ! |
---|
370 | FUNCTION ridders(sig) RESULT(sg) |
---|
371 | ! |
---|
372 | !------------------------------------------------------------------------------- |
---|
373 | IMPLICIT NONE |
---|
374 | !------------------------------------------------------------------------------- |
---|
375 | ! Purpose: Search for s solving (Pa/Preff)*s+(1-Pa/Preff)*EXP(1-1./s**2)=sg |
---|
376 | ! Notes: Uses Ridders' method, quite robust. Initial bracketing: 0<=sg<=1. |
---|
377 | ! Reference: Ridders, C. F. J. "A New Algorithm for Computing a Single Root of a |
---|
378 | ! Real Continuous Function" IEEE Trans. Circuits Systems 26, 979-980, 1979 |
---|
379 | !------------------------------------------------------------------------------- |
---|
380 | ! Arguments: |
---|
381 | REAL, INTENT(IN) :: sig(:) |
---|
382 | REAL :: sg(SIZE(sig)) |
---|
383 | !------------------------------------------------------------------------------- |
---|
384 | ! Local variables: |
---|
385 | INTEGER :: it, ns, maxit |
---|
386 | REAL :: c1, c2, x1, x2, x3, x4, f1, f2, f3, f4, s, xx, distrib |
---|
387 | !------------------------------------------------------------------------------- |
---|
388 | ns=SIZE(sig); maxit=9999 |
---|
389 | c1=Pa/Preff; c2=1.-c1 |
---|
390 | DO l=1,ns |
---|
391 | xx=HUGE(1.) |
---|
392 | x1=0.0; f1=distrib(x1,c1,c2,sig(l)) |
---|
393 | x2=1.0; f2=distrib(x2,c1,c2,sig(l)) |
---|
394 | DO it=1,maxit |
---|
395 | x3=0.5*(x1+x2); f3=distrib(x3,c1,c2,sig(l)) |
---|
396 | s=SQRT(f3**2-f1*f2); IF(s==0.) EXIT |
---|
397 | x4=x3+(x3-x1)*(SIGN(1.,f1-f2)*f3/s); IF(ABS(10.*LOG(x4-xx))<=1E-5) EXIT |
---|
398 | xx=x4; f4=distrib(x4,c1,c2,sig(l)); IF(f4==0.) EXIT |
---|
399 | IF(SIGN(f3,f4)/=f3) THEN; x1=x3; f1=f3; x2=xx; f2=f4 |
---|
400 | ELSE IF(SIGN(f1,f4)/=f1) THEN; x2=xx; f2=f4 |
---|
401 | ELSE IF(SIGN(f2,f4)/=f2) THEN; x1=xx; f1=f4 |
---|
402 | ELSE; CALL abort_gcm("ridders",'Algorithm failed (which is odd...', 1) |
---|
403 | END IF |
---|
404 | IF(ABS(10.*LOG(ABS(x2-x1)))<=1E-5) EXIT !--- ERROR ON SIG <= 0.01m |
---|
405 | END DO |
---|
406 | IF(it==maxit+1) WRITE(lunout,'(a,i3)')'WARNING in ridder: failed to converg& |
---|
407 | &e for level ',l |
---|
408 | sg(l)=xx |
---|
409 | END DO |
---|
410 | sg(1)=1.; sg(ns)=0. |
---|
411 | |
---|
412 | END FUNCTION ridders |
---|
413 | |
---|
414 | FUNCTION racinesig(sig) RESULT(sg) |
---|
415 | ! |
---|
416 | !------------------------------------------------------------------------------- |
---|
417 | IMPLICIT NONE |
---|
418 | !------------------------------------------------------------------------------- |
---|
419 | ! Fredho 2014/05/18 |
---|
420 | ! Purpose: Search for s solving (Pa/Preff)*sg+(1-Pa/Preff)*EXP(1-1./sg**2)=s |
---|
421 | ! Notes: Uses Newton Raphson search |
---|
422 | !------------------------------------------------------------------------------- |
---|
423 | ! Arguments: |
---|
424 | REAL, INTENT(IN) :: sig(:) |
---|
425 | REAL :: sg(SIZE(sig)) |
---|
426 | !------------------------------------------------------------------------------- |
---|
427 | ! Local variables: |
---|
428 | INTEGER :: it, ns, maxit |
---|
429 | REAL :: c1, c2, x1, x2, x3, x4, f1, f2, f3, f4, s, xx, distrib |
---|
430 | !------------------------------------------------------------------------------- |
---|
431 | ns=SIZE(sig); maxit=100 |
---|
432 | c1=Pa/Preff; c2=1.-c1 |
---|
433 | DO l=2,ns-1 |
---|
434 | sg(l)=sig(l) |
---|
435 | DO it=1,maxit |
---|
436 | f1=exp(1-1./sg(l)**2)*(1.-c1) |
---|
437 | sg(l)=sg(l)-(c1*sg(l)+f1-sig(l))/(c1+2*f1*sg(l)**(-3)) |
---|
438 | ENDDO |
---|
439 | ! print*,'SSSSIG ',sig(l),sg(l),c1*sg(l)+exp(1-1./sg(l)**2)*(1.-c1) |
---|
440 | ENDDO |
---|
441 | sg(1)=1.; sg(ns)=0. |
---|
442 | |
---|
443 | END FUNCTION racinesig |
---|
444 | |
---|
445 | |
---|
446 | |
---|
447 | |
---|
448 | END SUBROUTINE disvert |
---|
449 | |
---|
450 | !------------------------------------------------------------------------------- |
---|
451 | |
---|
452 | FUNCTION distrib(x,c1,c2,x0) RESULT(res) |
---|
453 | ! |
---|
454 | !------------------------------------------------------------------------------- |
---|
455 | ! Arguments: |
---|
456 | REAL, INTENT(IN) :: x, c1, c2, x0 |
---|
457 | REAL :: res |
---|
458 | !------------------------------------------------------------------------------- |
---|
459 | res=c1*x+c2*EXP(1-1/(x**2))-x0 |
---|
460 | |
---|
461 | END FUNCTION distrib |
---|
462 | |
---|
463 | |
---|