forked from erget/wgrib2
-
Notifications
You must be signed in to change notification settings - Fork 0
/
Copy pathpolateg0.f
executable file
·191 lines (191 loc) · 7.83 KB
/
polateg0.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
C-----------------------------------------------------------------------
SUBROUTINE POLATEG0(IPOPT,KGDSI,KGDSO,MI,MO,KM,IBI,LI,GI,
& NO,RLAT,RLON,CROT,SROT,IBO,LO,XO,YO,IRET)
C$$$ SUBPROGRAM DOCUMENTATION BLOCK
C
C SUBPROGRAM: POLATEG0 INTERPOLATE SCALAR FIELD GRADIENTS (BILINEAR)
C PRGMMR: IREDELL ORG: W/NMC23 DATE: 96-04-10
C
C ABSTRACT: THIS SUBPROGRAM PERFORMS BILINEAR INTERPOLATION
C FROM ANY GRID TO ANY GRID FOR SCALAR FIELDS,
C RETURNING THEIR VECTOR GRADIENTS.
C NO OPTIONS ARE ALLOWED.
C ONLY HORIZONTAL INTERPOLATION IS PERFORMED.
C THE GRIDS ARE DEFINED BY THEIR GRID DESCRIPTION SECTIONS
C (PASSED IN INTEGER FORM AS DECODED BY SUBPROGRAM W3FI63).
C THE CURRENT CODE RECOGNIZES THE FOLLOWING PROJECTIONS:
C (KGDS(1)=000) EQUIDISTANT CYLINDRICAL
C (KGDS(1)=001) MERCATOR CYLINDRICAL
C (KGDS(1)=003) LAMBERT CONFORMAL CONICAL
C (KGDS(1)=004) GAUSSIAN CYLINDRICAL (SPECTRAL NATIVE)
C (KGDS(1)=005) POLAR STEREOGRAPHIC AZIMUTHAL
C (KGDS(1)=202) ROTATED EQUIDISTANT CYLINDRICAL (ETA NATIVE)
C WHERE KGDS COULD BE EITHER INPUT KGDSI OR OUTPUT KGDSO.
C AS AN ADDED BONUS THE NUMBER OF OUTPUT GRID POINTS
C AND THEIR LATITUDES AND LONGITUDES ARE ALSO RETURNED.
C ON THE OTHER HAND, THE OUTPUT CAN BE A SET OF STATION POINTS
C IF KGDSO(1)<0, IN WHICH CASE THE NUMBER OF POINTS
C AND THEIR LATITUDES AND LONGITUDES MUST BE INPUT.
C INPUT BITMAPS WILL BE INTERPOLATED TO OUTPUT BITMAPS.
C OUTPUT BITMAPS WILL ALSO BE CREATED WHEN THE OUTPUT GRID
C EXTENDS OUTSIDE OF THE DOMAIN OF THE INPUT GRID.
C THE OUTPUT FIELD IS SET TO 0 WHERE THE OUTPUT BITMAP IS OFF.
C
C PROGRAM HISTORY LOG:
C 96-04-10 IREDELL
C 1999-04-08 IREDELL SPLIT IJKGDS INTO TWO PIECES
C 2001-06-18 IREDELL FIXED CALL TO IJKGDS1
C
C USAGE: CALL POLATEG0(IPOPT,KGDSI,KGDSO,MI,MO,KM,IBI,LI,GI,
C & NO,RLAT,RLON,CROT,SROT,IBO,LO,XO,YO,IRET)
C
C INPUT ARGUMENT LIST:
C IPOPT - INTEGER (20) INTERPOLATION OPTIONS (NO OPTIONS)
C KGDSI - INTEGER (200) INPUT GDS PARAMETERS AS DECODED BY W3FI63
C KGDSO - INTEGER (200) OUTPUT GDS PARAMETERS
C (KGDSO(1)<0 IMPLIES RANDOM STATION POINTS)
C MI - INTEGER SKIP NUMBER BETWEEN INPUT GRID FIELDS IF KM>1
C OR DIMENSION OF INPUT GRID FIELDS IF KM=1
C MO - INTEGER SKIP NUMBER BETWEEN OUTPUT GRID FIELDS IF KM>1
C OR DIMENSION OF OUTPUT GRID FIELDS IF KM=1
C KM - INTEGER NUMBER OF FIELDS TO INTERPOLATE
C IBI - INTEGER (KM) INPUT BITMAP FLAGS
C LI - LOGICAL*1 (MI,KM) INPUT BITMAPS (IF SOME IBI(K)=1)
C GI - REAL (MI,KM) INPUT FIELDS TO INTERPOLATE
C NO - INTEGER NUMBER OF OUTPUT POINTS (ONLY IF KGDSO(1)<0)
C RLAT - REAL (NO) OUTPUT LATITUDES IN DEGREES (IF KGDSO(1)<0)
C RLON - REAL (NO) OUTPUT LONGITUDES IN DEGREES (IF KGDSO(1)<0)
C CROT - REAL (NO) VECTOR ROTATION COSINES (IF KGDSO(1)<0)
C SROT - REAL (NO) VECTOR ROTATION SINES (IF KGDSO(1)<0)
C (UGRID=CROT*UEARTH-SROT*VEARTH;
C VGRID=SROT*UEARTH+CROT*VEARTH)
C
C OUTPUT ARGUMENT LIST:
C NO - INTEGER NUMBER OF OUTPUT POINTS (ONLY IF KGDSO(1)>=0)
C RLAT - REAL (MO) OUTPUT LATITUDES IN DEGREES (IF KGDSO(1)>=0)
C RLON - REAL (MO) OUTPUT LONGITUDES IN DEGREES (IF KGDSO(1)>=0)
C IBO - INTEGER (KM) OUTPUT BITMAP FLAGS
C LO - LOGICAL*1 (MO,KM) OUTPUT BITMAPS (ALWAYS OUTPUT)
C XO - REAL (MO,KM) OUTPUT X-GRADIENT FIELDS INTERPOLATED
C YO - REAL (MO,KM) OUTPUT Y-GRADIENT FIELDS INTERPOLATED
C IRET - INTEGER RETURN CODE
C 0 SUCCESSFUL INTERPOLATION
C 2 UNRECOGNIZED INPUT GRID OR NO GRID OVERLAP
C 3 UNRECOGNIZED OUTPUT GRID
C
C SUBPROGRAMS CALLED:
C GDSWZD GRID DESCRIPTION SECTION WIZARD
C IJKGDS0 SET UP PARAMETERS FOR IJKGDS1
C (IJKGDS1) RETURN FIELD POSITION FOR A GIVEN GRID POINT
C POLFIXS MAKE MULTIPLE POLE SCALAR VALUES CONSISTENT
C
C REMARKS: THE GRADIENT COMPUTATIONS ARE NOT ROBUST NEAR THE POLES.
C IN FACT, NO GRADIENTS ARE COMPUTED POLEWARD OF 89 LATITUDE.
C
C ATTRIBUTES:
C LANGUAGE: FORTRAN 77
C
C$$$
CFPP$ EXPAND(IJKGDS1)
INTEGER IPOPT(20)
INTEGER KGDSI(200),KGDSO(200)
INTEGER IBI(KM),IBO(KM)
LOGICAL*1 LI(MI,KM),LO(MO,KM)
REAL GI(MI,KM),XO(MO,KM),YO(MO,KM)
REAL RLAT(MO),RLON(MO)
REAL CROT(MO),SROT(MO)
REAL CLAT(MO)
REAL XPTS(MO),YPTS(MO)
REAL XLON(MO),XLAT(MO)
REAL YLON(MO),YLAT(MO)
INTEGER N11(MO),N21(MO),N12(MO),N22(MO)
REAL WX11(MO),WX21(MO),WX12(MO),WX22(MO)
REAL WY11(MO),WY21(MO),WY12(MO),WY22(MO)
INTEGER IJKGDSA(20)
PARAMETER(FILL=-9999.)
PARAMETER(PLAT=89.)
PARAMETER(RERTH=6.3712E6)
C - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
C COMPUTE NUMBER OF OUTPUT POINTS AND THEIR LATITUDES AND LONGITUDES.
IRET=0
IF(KGDSO(1).GE.0) THEN
CALL GDSWZD(KGDSO, 0,MO,FILL,XPTS,YPTS,RLON,RLAT,NO,1,CROT,SROT,
& 0,XLON,XLAT,YLON,YLAT)
IF(NO.EQ.0) IRET=3
ENDIF
C - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
C LOCATE INPUT POINTS AND COMPUTE THEIR WEIGHTS
DPR=180/ACOS(-1.)
DO N=1,NO
CLAT(N)=COS(RLAT(N)/DPR)
ENDDO
CALL GDSWZD(KGDSI,-1,NO,FILL,XPTS,YPTS,RLON,RLAT,NV,0,DUM,DUM,
& 1,XLON,XLAT,YLON,YLAT)
IF(IRET.EQ.0.AND.NV.EQ.0) IRET=2
CALL IJKGDS0(KGDSI,IJKGDSA)
DO N=1,NO
XI=XPTS(N)
YI=YPTS(N)
IF(XI.NE.FILL.AND.YI.NE.FILL.AND.ABS(RLAT(N)).LE.PLAT) THEN
I1=XI
I2=I1+1
J1=YI
J2=J1+1
XF=XI-I1
YF=YI-J1
N11(N)=IJKGDS1(I1,J1,IJKGDSA)
N21(N)=IJKGDS1(I2,J1,IJKGDSA)
N12(N)=IJKGDS1(I1,J2,IJKGDSA)
N22(N)=IJKGDS1(I2,J2,IJKGDSA)
IF(MIN(N11(N),N21(N),N12(N),N22(N)).GT.0) THEN
FACX=DPR/(RERTH*CLAT(N))
WX11(N)=(-(1-YF)*XLON(N)-(1-XF)*YLON(N))*FACX
WX21(N)=((1-YF)*XLON(N)-XF*YLON(N))*FACX
WX12(N)=(-YF*XLON(N)+(1-XF)*YLON(N))*FACX
WX22(N)=(YF*XLON(N)+XF*YLON(N))*FACX
FACY=DPR/RERTH
WY11(N)=(-(1-YF)*XLAT(N)-(1-XF)*YLAT(N))*FACY
WY21(N)=((1-YF)*XLAT(N)-XF*YLAT(N))*FACY
WY12(N)=(-YF*XLAT(N)+(1-XF)*YLAT(N))*FACY
WY22(N)=(YF*XLAT(N)+XF*YLAT(N))*FACY
ELSE
N11(N)=0
N21(N)=0
N12(N)=0
N22(N)=0
ENDIF
ELSE
N11(N)=0
N21(N)=0
N12(N)=0
N22(N)=0
ENDIF
ENDDO
C - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
C INTERPOLATE WITH OR WITHOUT BITMAPS
CMIC$ DO ALL AUTOSCOPE
DO K=1,KM
IBO(K)=0
DO N=1,NO
LO(N,K)=N11(N).GT.0.AND.(IBI(K).EQ.0.OR.
& (LI(N11(N),K).AND.LI(N21(N),K).AND.
& LI(N12(N),K).AND.LI(N22(N),K)))
IF(LO(N,K)) THEN
XO(N,K)=WX11(N)*GI(N11(N),K)+WX21(N)*GI(N21(N),K)
& +WX12(N)*GI(N12(N),K)+WX22(N)*GI(N22(N),K)
YO(N,K)=WY11(N)*GI(N11(N),K)+WY21(N)*GI(N21(N),K)
& +WY12(N)*GI(N12(N),K)+WY22(N)*GI(N22(N),K)
XROT=CROT(N)*XO(N,K)-SROT(N)*YO(N,K)
YROT=SROT(N)*XO(N,K)+CROT(N)*YO(N,K)
XO(N,K)=XROT
YO(N,K)=YROT
ELSE
IBO(K)=1
XO(N,K)=0.
YO(N,K)=0.
ENDIF
ENDDO
ENDDO
IF(KGDSO(1).EQ.0) CALL POLFIXV(NO,MO,KM,RLAT,RLON,IBO,LO,XO,YO)
C - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
END