forked from erget/wgrib2
-
Notifications
You must be signed in to change notification settings - Fork 0
/
Copy pathgdswzdcb.f
executable file
·322 lines (320 loc) · 12.6 KB
/
gdswzdcb.f
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
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
C-----------------------------------------------------------------------
SUBROUTINE GDSWZDCB(KGDS,IOPT,NPTS,FILL,XPTS,YPTS,RLON,RLAT,NRET,
& LROT,CROT,SROT,LMAP,XLON,XLAT,YLON,YLAT,AREA)
C$$$ SUBPROGRAM DOCUMENTATION BLOCK
C
C SUBPROGRAM: GDSWZDCB GDS WIZARD FOR ROTATED EQUIDISTANT CYLINDRICAL
C PRGMMR: IREDELL ORG: W/NMC23 DATE: 96-04-10
C
C ABSTRACT: THIS SUBPROGRAM DECODES THE GRIB GRID DESCRIPTION SECTION
C (PASSED IN INTEGER FORM AS DECODED BY SUBPROGRAM W3FI63)
C AND RETURNS ONE OF THE FOLLOWING:
C (IOPT=+1) EARTH COORDINATES OF SELECTED GRID COORDINATES
C (IOPT=-1) GRID COORDINATES OF SELECTED EARTH COORDINATES
C FOR STAGGERED ROTATED EQUIDISTANT CYLINDRICAL PROJECTIONS.
C (SEE UNDER THE DESCRIPTION OF KGDS TO DETERMINE WHETHER
C TO COMPUTE A STAGGERED WIND GRID OR A STAGGERED MASS GRID.)
C IF THE SELECTED COORDINATES ARE MORE THAN ONE GRIDPOINT
C BEYOND THE THE EDGES OF THE GRID DOMAIN, THEN THE RELEVANT
C OUTPUT ELEMENTS ARE SET TO FILL VALUES.
C THE ACTUAL NUMBER OF VALID POINTS COMPUTED IS RETURNED TOO.
C OPTIONALLY, THE VECTOR ROTATIONS AND THE MAP JACOBIANS
C FOR THIS GRID MAY BE RETURNED AS WELL.
C
C PROGRAM HISTORY LOG:
C 96-04-10 IREDELL
C 97-10-20 IREDELL INCLUDE MAP OPTIONS
C 98-08-19 BALDWIN MODIFY GDSWZDC9 FOR TYPE 203 ETA GRIDS
C 2003-06-11 IREDELL INCREASE PRECISION
C
C USAGE: CALL GDSWZDCB(KGDS,IOPT,NPTS,FILL,XPTS,YPTS,RLON,RLAT,NRET,
C & LROT,CROT,SROT,LMAP,XLON,XLAT,YLON,YLAT,AREA)
C
C INPUT ARGUMENT LIST:
C KGDS - INTEGER (200) GDS PARAMETERS AS DECODED BY W3FI63
C IMPORTANT NOTE: IF THE 9TH BIT (FROM RIGHT) OF KGDS(11)
C (SCANNING MODE FLAG) IS 1, THEN THIS
C THE GRID IS COMPUTED FOR A WIND FIELD;
C OTHERWISE IT IS FOR A MASS FIELD. THUS
C MOD(KGDS(11)/256,2)=0 FOR MASS GRID.
C IOPT - INTEGER OPTION FLAG
C (+1 TO COMPUTE EARTH COORDS OF SELECTED GRID COORDS)
C (-1 TO COMPUTE GRID COORDS OF SELECTED EARTH COORDS)
C NPTS - INTEGER MAXIMUM NUMBER OF COORDINATES
C FILL - REAL FILL VALUE TO SET INVALID OUTPUT DATA
C (MUST BE IMPOSSIBLE VALUE; SUGGESTED VALUE: -9999.)
C XPTS - REAL (NPTS) GRID X POINT COORDINATES IF IOPT>0
C YPTS - REAL (NPTS) GRID Y POINT COORDINATES IF IOPT>0
C RLON - REAL (NPTS) EARTH LONGITUDES IN DEGREES E IF IOPT<0
C (ACCEPTABLE RANGE: -360. TO 360.)
C RLAT - REAL (NPTS) EARTH LATITUDES IN DEGREES N IF IOPT<0
C (ACCEPTABLE RANGE: -90. TO 90.)
C LROT - INTEGER FLAG TO RETURN VECTOR ROTATIONS IF 1
C LMAP - INTEGER FLAG TO RETURN MAP JACOBIANS IF 1
C
C OUTPUT ARGUMENT LIST:
C XPTS - REAL (NPTS) GRID X POINT COORDINATES IF IOPT<0
C YPTS - REAL (NPTS) GRID Y POINT COORDINATES IF IOPT<0
C RLON - REAL (NPTS) EARTH LONGITUDES IN DEGREES E IF IOPT>0
C RLAT - REAL (NPTS) EARTH LATITUDES IN DEGREES N IF IOPT>0
C NRET - INTEGER NUMBER OF VALID POINTS COMPUTED
C CROT - REAL (NPTS) CLOCKWISE VECTOR ROTATION COSINES IF LROT=1
C SROT - REAL (NPTS) CLOCKWISE VECTOR ROTATION SINES IF LROT=1
C (UGRID=CROT*UEARTH-SROT*VEARTH;
C VGRID=SROT*UEARTH+CROT*VEARTH)
C XLON - REAL (NPTS) DX/DLON IN 1/DEGREES IF LMAP=1
C XLAT - REAL (NPTS) DX/DLAT IN 1/DEGREES IF LMAP=1
C YLON - REAL (NPTS) DY/DLON IN 1/DEGREES IF LMAP=1
C YLAT - REAL (NPTS) DY/DLAT IN 1/DEGREES IF LMAP=1
C AREA - REAL (NPTS) AREA WEIGHTS IN M**2 IF LMAP=1
C
C ATTRIBUTES:
C LANGUAGE: FORTRAN 77
C
C$$$
INTEGER KGDS(200)
REAL XPTS(NPTS),YPTS(NPTS),RLON(NPTS),RLAT(NPTS)
REAL CROT(NPTS),SROT(NPTS)
REAL XLON(NPTS),XLAT(NPTS),YLON(NPTS),YLAT(NPTS),AREA(NPTS)
INTEGER,PARAMETER:: KD=SELECTED_REAL_KIND(15,45)
REAL(KIND=KD):: RERTH,PI,DPR
REAL(KIND=KD):: RLAT1,RLON1,RLAT0,RLON0
REAL(KIND=KD):: SLAT1,CLAT1,SLAT0,CLAT0
REAL(KIND=KD):: CLON1,SLATR,CLATR,CLONR
REAL(KIND=KD):: RLATR,RLONR,DLATS,DLONS,XPTFC,YPTFC,SLON
REAL(KIND=KD):: SLAT,CLAT,CLON,RLATCR,RLONCR,DMIDS,RLATLR,RLONLR
REAL(KIND=KD):: TERM1,TERM2
REAL(KIND=KD):: XLONF,XLATF,YLONF,YLATF
PARAMETER(RERTH=6.3712E6_KD)
PARAMETER(PI=3.14159265358979_KD,DPR=180._KD/PI)
C - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
IF(KGDS(1).EQ.203) THEN
RLAT1=KGDS(4)*1.E-3_KD
RLON1=KGDS(5)*1.E-3_KD
RLAT0=KGDS(7)*1.E-3_KD
RLON0=KGDS(8)*1.E-3_KD
DLONS=KGDS(9)*1.E-3_KD
DLATS=KGDS(10)*1.E-3_KD
DMIDS=SQRT(DLONS*DLONS+DLATS*DLATS)
IROT=MOD(KGDS(6)/8,2)
IM=KGDS(2)*2-1
JM=KGDS(3)
KSCAN=MOD(KGDS(11)/256,2)
ISCAN=MOD(KGDS(11)/128,2)
JSCAN=MOD(KGDS(11)/64,2)
NSCAN=MOD(KGDS(11)/32,2)
HI=(-1.)**ISCAN
HJ=(-1.)**(1-JSCAN)
SLAT1=SIN(RLAT1/DPR)
CLAT1=COS(RLAT1/DPR)
SLAT0=SIN(RLAT0/DPR)
CLAT0=COS(RLAT0/DPR)
HS0=SIGN(1._KD,MOD(RLON1-RLON0+180+3600,360._KD)-180)
CLON1=COS((RLON1-RLON0)/DPR)
SLATR=CLAT0*SLAT1-SLAT0*CLAT1*CLON1
CLATR=SQRT(1-SLATR**2)
CLONR=(CLAT0*CLAT1*CLON1+SLAT0*SLAT1)/CLATR
RLATLR=DPR*ASIN(MAX(MIN(SLATR,1.0_KD),-1.0_KD))
RLATCR=RLATLR+(JM-1)/2.*DLATS
RLONLR=HS0*DPR*ACOS(MAX(MIN(CLONR,1.0_KD),-1.0_KD))
RLONCR=RLONLR+(IM-1)/2.*DLONS
C DLATS=RLATR/(-(JM-1)/2)
C DLONS=RLONR/(-(IM-1)/2)
write(0,*) 'in gdswzdcb.f'
write(0,*) 'rlatcr=',rlatcr,' rloncr=',rloncr
write(0,*) 'dlons=',dlons,' dlats=',dlats
IF(KSCAN.EQ.0) THEN
IS1=(JM+1)/2
ELSE
IS1=JM/2
ENDIF
XMIN=0
XMAX=IM+1
IF(IM.EQ.NINT(360/ABS(DLONS))) XMAX=IM+2
YMIN=0
YMAX=JM+1
NRET=0
C - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
C TRANSLATE GRID COORDINATES TO EARTH COORDINATES
IF(IOPT.EQ.0.OR.IOPT.EQ.1) THEN
C Calculate grid center point in rotated coordinates:
XPTFC=(JM-1)/2. + ( (IM-1)/2. - IS1 )
YPTFC=(JM-1)/2. - ( (IM-1)/2. - IS1 ) + KSCAN
DO N=1,NPTS
XPTF=YPTS(N)+(XPTS(N)-IS1)
YPTF=YPTS(N)-(XPTS(N)-IS1)+KSCAN
IF(XPTF.GE.XMIN.AND.XPTF.LE.XMAX.AND.
& YPTF.GE.YMIN.AND.YPTF.LE.YMAX) THEN
c$$$ HS=HI*SIGN(1.,XPTF-(IM+1)/2)
c$$$ RLONR=(XPTF-(IM+1)/2)*DLONS
c$$$ RLATR=(YPTF-(JM+1)/2)*DLATS
HS=HI*SIGN(1._KD,XPTFC+XPTF-1)
RLONR=(XPTF-(IM+1)/2)*DLONS+RLONCR
RLATR=(YPTF-(JM+1)/2)*DLATS+RLATCR
CLONR=COS(RLONR/DPR)
SLATR=SIN(RLATR/DPR)
CLATR=COS(RLATR/DPR)
SLAT=CLAT0*SLATR+SLAT0*CLATR*CLONR
IF(SLAT.LE.-1) THEN
CLAT=0.
CLON=COS(RLON0/DPR)
RLON(N)=0
RLAT(N)=-90
ELSEIF(SLAT.GE.1) THEN
CLAT=0.
CLON=COS(RLON0/DPR)
RLON(N)=0
RLAT(N)=90
ELSE
CLAT=SQRT(1-SLAT**2)
CLON=(CLAT0*CLATR*CLONR-SLAT0*SLATR)/CLAT
CLON=MIN(MAX(CLON,-1._KD),1._KD)
RLON(N)=MOD(RLON0+HS*DPR*ACOS(MAX(MIN(CLON,1.0_KD),
& -1.0_KD))+3600,360._KD)
RLAT(N)=DPR*ASIN(MAX(MIN(SLAT,1.0_KD),-1.0_KD))
ENDIF
NRET=NRET+1
IF(LROT.EQ.1) THEN
IF(IROT.EQ.1) THEN
IF(CLATR.LE.0) THEN
CROT(N)=-SIGN(1._KD,SLATR*SLAT0)
SROT(N)=0
ELSE
SLON=SIN((RLON(N)-RLON0)/DPR)
CROT(N)=(CLAT0*CLAT+SLAT0*SLAT*CLON)/CLATR
SROT(N)=SLAT0*SLON/CLATR
ENDIF
ELSE
CROT(N)=1
SROT(N)=0
ENDIF
ENDIF
IF(LMAP.EQ.1) THEN
IF(CLATR.LE.0) THEN
XLON(N)=FILL
XLAT(N)=FILL
YLON(N)=FILL
YLAT(N)=FILL
AREA(N)=FILL
ELSE
SLON=SIN((RLON(N)-RLON0)/DPR)
TERM1=(CLAT0*CLAT+SLAT0*SLAT*CLON)/CLATR
TERM2=SLAT0*SLON/CLATR
XLONF=TERM1*CLAT/(DLONS*CLATR)
XLATF=-TERM2/(DLONS*CLATR)
YLONF=TERM2*CLAT/DLATS
YLATF=TERM1/DLATS
XLON(N)=XLONF-YLONF
XLAT(N)=XLATF-YLATF
YLON(N)=XLONF+YLONF
YLAT(N)=XLATF+YLATF
AREA(N)=RERTH**2*CLATR*DLATS*DLONS*2/DPR**2
ENDIF
ENDIF
ELSE
RLON(N)=FILL
RLAT(N)=FILL
ENDIF
ENDDO
C - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
C TRANSLATE EARTH COORDINATES TO GRID COORDINATES
ELSEIF(IOPT.EQ.-1) THEN
DO N=1,NPTS
IF(ABS(RLON(N)).LE.360.AND.ABS(RLAT(N)).LE.90) THEN
HS=SIGN(1._KD,MOD(RLON(N)-RLON0+180+3600,360._KD)-180)
CLON=COS((RLON(N)-RLON0)/DPR)
SLAT=SIN(RLAT(N)/DPR)
CLAT=COS(RLAT(N)/DPR)
SLATR=CLAT0*SLAT-SLAT0*CLAT*CLON
IF(SLATR.LE.-1) THEN
CLATR=0.
RLONR=0
RLATR=-90
ELSEIF(SLATR.GE.1) THEN
CLATR=0.
RLONR=0
RLATR=90
ELSE
CLATR=SQRT(1-SLATR**2)
CLONR=(CLAT0*CLAT*CLON+SLAT0*SLAT)/CLATR
CLONR=MIN(MAX(CLONR,-1._KD),1._KD)
RLONR=HS*DPR*ACOS(MAX(MIN(CLONR,1.0_KD),-1.0_KD))
RLATR=DPR*ASIN(MAX(MIN(SLATR,1.0_KD),-1.0_KD))
ENDIF
c$$$ XPTF=(IM+1)/2+RLONR/DLONS
c$$$ YPTF=(JM+1)/2+RLATR/DLATS
XPTF=(RLONR-RLONLR)/DLONS+1
YPTF=(RLATR-RLATLR)/DLATS+1
c$$$ XPTF=(IM+1)/2+(RLONR-RLONCR)/DLONS
c$$$ YPTF=(JM+1)/2+(RLATR-RLATCR)/DLATS
IF(XPTF.GE.XMIN.AND.XPTF.LE.XMAX.AND.
& YPTF.GE.YMIN.AND.YPTF.LE.YMAX) THEN
XPTS(N)=IS1+(XPTF-(YPTF-KSCAN))/2
YPTS(N)=(XPTF+(YPTF-KSCAN))/2
NRET=NRET+1
IF(LROT.EQ.1) THEN
IF(IROT.EQ.1) THEN
IF(CLATR.LE.0) THEN
CROT(N)=-SIGN(1._KD,SLATR*SLAT0)
SROT(N)=0
ELSE
SLON=SIN((RLON(N)-RLON0)/DPR)
CROT(N)=(CLAT0*CLAT+SLAT0*SLAT*CLON)/CLATR
SROT(N)=SLAT0*SLON/CLATR
ENDIF
ELSE
CROT(N)=1
SROT(N)=0
ENDIF
ENDIF
IF(LMAP.EQ.1) THEN
IF(CLATR.LE.0) THEN
XLON(N)=FILL
XLAT(N)=FILL
YLON(N)=FILL
YLAT(N)=FILL
AREA(N)=FILL
ELSE
SLON=SIN((RLON(N)-RLON0)/DPR)
TERM1=(CLAT0*CLAT+SLAT0*SLAT*CLON)/CLATR
TERM2=SLAT0*SLON/CLATR
XLONF=TERM1*CLAT/(DLONS*CLATR)
XLATF=-TERM2/(DLONS*CLATR)
YLONF=TERM2*CLAT/DLATS
YLATF=TERM1/DLATS
XLON(N)=XLONF-YLONF
XLAT(N)=XLATF-YLATF
YLON(N)=XLONF+YLONF
YLAT(N)=XLATF+YLATF
AREA(N)=RERTH**2*CLATR*DLATS*DLONS*2/DPR**2
ENDIF
ENDIF
ELSE
XPTS(N)=FILL
YPTS(N)=FILL
ENDIF
ELSE
XPTS(N)=FILL
YPTS(N)=FILL
ENDIF
ENDDO
ENDIF
C - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
C PROJECTION UNRECOGNIZED
ELSE
IRET=-1
IF(IOPT.GE.0) THEN
DO N=1,NPTS
RLON(N)=FILL
RLAT(N)=FILL
ENDDO
ENDIF
IF(IOPT.LE.0) THEN
DO N=1,NPTS
XPTS(N)=FILL
YPTS(N)=FILL
ENDDO
ENDIF
ENDIF
C - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
END