[59] | 1 | ;--------- |
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| 2 | ;+ |
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[101] | 3 | ; @file_comments north stereographic polar projection |
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[59] | 4 | ; |
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[101] | 5 | ; @keyword /DOUBLE use double precision (default is float) |
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[59] | 6 | ; |
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[101] | 7 | ; @returns |
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[59] | 8 | ; gsinu,gcosu : sinus and cosinus of the angle |
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| 9 | ; gsinv,gcosv between north-south direction |
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| 10 | ; gsint,gcost and the j-direction of the mesh |
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| 11 | ; |
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[101] | 12 | ; @restrictions to compute the lateral boundary conditions, we assume |
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[59] | 13 | ; that: |
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| 14 | ; (1) the first line is similar to the second line |
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| 15 | ; => gcosu[*, 0] = gcosu[*, 1] |
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| 16 | ; => gsinu[*, 0] = gsinu[*, 1] |
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| 17 | ; (2) the grid follows OPA x periodicity rule, first column is |
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| 18 | ; equal to the next to last column |
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| 19 | ; => gcosv[0, *] = gcosv[jpj-2, *] |
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| 20 | ; => gsinv[0, *] = gsinv[jpj-2, *] |
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| 21 | ; |
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| 22 | ; |
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[101] | 23 | ; @history |
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[59] | 24 | ; -------------- |
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| 25 | ; Original : 96-07 (O. Marti) |
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| 26 | ; 98-06 (G. Madec) |
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| 27 | ; Feb 2005: IDL adaptation S. Masson |
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| 28 | ;- |
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| 29 | ;--------- |
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| 30 | ; |
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| 31 | FUNCTION fsnspp, plam, pphi, DOUBLE = double |
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| 32 | IF keyword_set(double) THEN BEGIN |
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| 33 | a = 2.d * tan( !dpi/4.d - !dpi/180.d*pphi/2.d ) |
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| 34 | x = cos( !dpi/180.d*plam ) * a |
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| 35 | y = sin( !dpi/180.d*plam ) * a |
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| 36 | ENDIF ELSE BEGIN |
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| 37 | a = 2. * tan( !pi/4. - !pi/180.*float(pphi)/2. ) |
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| 38 | x = cos( !pi/180.*float(plam) ) * a |
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| 39 | y = sin( !pi/180.*float(plam) ) * a |
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| 40 | ENDELSE |
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| 41 | RETURN, {x:x, y:y} |
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| 42 | END |
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| 43 | ;--------- |
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[101] | 44 | ;+ |
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| 45 | ; @file_comments Compute angles between grid lines and direction of the North |
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| 46 | ;(fom angle.F,v 2.2 in OPA8.2) |
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| 47 | ; |
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| 48 | ; @param fileocemesh {in}{required} a netcdf file that contains (at least): |
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| 49 | ; glamu, gphiu: longitudes and latitudes at U-points |
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| 50 | ; glamv, gphiv: longitudes and latitudes at V-points |
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| 51 | ; glamf, gphif: longitudes and latitudes at F-points |
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| 52 | ; |
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| 53 | ; @keyword IODIRECTORY the directory path where is located fileocemesh |
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| 54 | ; @keyword /DOUBLE use double precision (default is float) |
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| 55 | ;- |
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[59] | 56 | ;--------- |
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| 57 | ; |
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| 58 | PRO angle, fileocemesh, gcosu, gsinu, gcosv, gsinv, gcost, gsint $ |
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| 59 | , IODIRECTORY = iodirectory, DOUBLE = double |
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| 60 | ; |
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| 61 | ; 0. read oceanic grid parameters |
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| 62 | ; ================================ |
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| 63 | ; |
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| 64 | IF keyword_set(IODIRECTORY) THEN BEGIN |
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| 65 | IF strpos(iodirectory,'/',/reverse_search) NE (strlen(iodirectory)-1) THEN $ |
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| 66 | iodirectory = iodirectory+'/' |
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| 67 | ENDIF ELSE iodirectory = '' |
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| 68 | fileoce = iodirectory+fileocemesh |
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| 69 | ; |
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| 70 | fileoce = findfile(fileoce, count = okfile) |
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| 71 | IF okfile NE 1 THEN BEGIN |
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| 72 | print, 'the file '+fileoce+' is not found... we stop' |
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| 73 | stop |
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| 74 | ENDIF |
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| 75 | ; |
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| 76 | cdfido = ncdf_open(fileoce[0]) |
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| 77 | ncdf_varget, cdfido, 'glamt', glamt |
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| 78 | ncdf_varget, cdfido, 'glamu', glamu |
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| 79 | ncdf_varget, cdfido, 'glamv', glamv |
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| 80 | ncdf_varget, cdfido, 'glamf', glamf |
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| 81 | ncdf_varget, cdfido, 'gphit', gphit |
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| 82 | ncdf_varget, cdfido, 'gphiu', gphiu |
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| 83 | ncdf_varget, cdfido, 'gphiv', gphiv |
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| 84 | ncdf_varget, cdfido, 'gphif', gphif |
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| 85 | ncdf_close, cdfido |
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| 86 | ; |
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| 87 | glamt = reform(glamt, /over) |
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| 88 | glamu = reform(glamu, /over) |
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| 89 | glamv = reform(glamv, /over) |
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| 90 | glamf = reform(glamf, /over) |
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| 91 | gphit = reform(gphit, /over) |
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| 92 | gphiu = reform(gphiu, /over) |
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| 93 | gphiv = reform(gphiv, /over) |
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| 94 | gphif = reform(gphif, /over) |
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| 95 | jpj = (size(glamf, /dimension))[1] |
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| 96 | ; |
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| 97 | ; I. Compute the cosinus and sinus |
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| 98 | ; ================================ |
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| 99 | ; (computation done on the north stereographic polar plan |
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| 100 | ; |
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| 101 | ; ... north pole direction & modulous (at t-point) |
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| 102 | znpt = fsnspp( glamt, gphit, DOUBLE = double ) |
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| 103 | glamt = -1 & gphit = -1; free memory |
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| 104 | znpt.x = - znpt.x |
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| 105 | znpt.y = - znpt.y |
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| 106 | znnpt = znpt.x*znpt.x + znpt.y*znpt.y |
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| 107 | ; ... north pole direction & modulous (at u-point) |
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| 108 | znpu = fsnspp( glamu, gphiu, DOUBLE = double ) |
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| 109 | glamu = -1 & gphiu = -1; free memory |
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| 110 | znpu.x = - znpu.x |
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| 111 | znpu.y = - znpu.y |
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| 112 | znnpu = znpu.x*znpu.x + znpu.y*znpu.y |
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| 113 | ; ... north pole direction & modulous (at v-point) |
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| 114 | znpv = fsnspp( glamv, gphiv, DOUBLE = double ) |
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| 115 | znpv00 = znpv |
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| 116 | znpv01 = fsnspp( shift(glamv, 0, 1), shift(gphiv, 0, 1), DOUBLE = double ) |
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| 117 | glamv = -1 & gphiv = -1; free memory |
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| 118 | znpv.x = - znpv.x |
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| 119 | znpv.y = - znpv.y |
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| 120 | znnpv = znpv.x*znpv.x + znpv.y*znpv.y |
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| 121 | ; ... f-point |
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| 122 | znpf00 = fsnspp( glamf, gphif, DOUBLE = double ) |
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| 123 | znpf01 = fsnspp( shift(glamf, 0, 1), shift(gphif, 0, 1), DOUBLE = double ) |
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| 124 | znpf10 = fsnspp( shift(glamf, 1, 0), shift(gphif, 1, 0), DOUBLE = double ) |
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| 125 | glamf = -1 & gphif = -1; free memory |
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| 126 | ; ... j-direction: v-point segment direction (t-point) |
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| 127 | zxvvt = znpv00.x - znpv01.x |
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| 128 | zyvvt = znpv00.y - znpv01.y |
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| 129 | zmnpvt = sqrt ( temporary(znnpt) * ( zxvvt*zxvvt + zyvvt*zyvvt ) ) |
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| 130 | znpv00 = -1; free memory |
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| 131 | znpv01 = -1; free memory |
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| 132 | IF keyword_set(double) THEN zmnpvt = 1.e-14 > zmnpvt $ |
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| 133 | ELSE zmnpvt = 1.e-6 > zmnpvt |
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| 134 | ; ... j-direction: f-point segment direction (u-point) |
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| 135 | zxffu = znpf00.x - znpf01.x |
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| 136 | zyffu = znpf00.y - znpf01.y |
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| 137 | zmnpfu = sqrt ( temporary(znnpu) * ( zxffu*zxffu + zyffu*zyffu ) ) |
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| 138 | znpf01 = -1; free memory |
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| 139 | IF keyword_set(double) THEN zmnpfu = 1.e-14 > zmnpfu $ |
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| 140 | ELSE zmnpfu = 1.e-6 > zmnpfu |
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| 141 | ; ... i-direction: f-point segment direction (v-point) |
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| 142 | zxffv = znpf00.x - znpf10.x |
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| 143 | zyffv = znpf00.y - znpf10.y |
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| 144 | znpf00 = -1 & znpf10 = -1; free memory |
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| 145 | zmnpfv = sqrt ( temporary(znnpv) * ( zxffv*zxffv + zyffv*zyffv ) ) |
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| 146 | IF keyword_set(double) THEN zmnpfv = 1.e-14 > zmnpfv $ |
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| 147 | ELSE zmnpfv = 1.e-6 > zmnpfv |
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| 148 | ; ... cosinus and sinus using scalar and vectorial products |
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| 149 | gsint = ( znpt.x*zyvvt - znpt.y*zxvvt ) / zmnpvt |
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| 150 | gcost = ( znpt.x*zxvvt + znpt.y*zyvvt ) / zmnpvt |
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| 151 | ; ... cosinus and sinus using scalar and vectorial products |
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| 152 | gsinu = ( znpu.x*zyffu - znpu.y*zxffu ) / zmnpfu |
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| 153 | gcosu = ( znpu.x*zxffu + znpu.y*zyffu ) / zmnpfu |
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| 154 | ; ... cosinus and sinus using scalar and vectorial products |
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| 155 | ; (caution, rotation of 90 degres) |
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| 156 | gsinv = ( znpv.x*zxffv + znpv.y*zyffv ) / zmnpfv |
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| 157 | gcosv = -( znpv.x*zyffv - znpv.y*zxffv ) / zmnpfv |
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| 158 | ; |
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| 159 | ; II. Geographic mesh |
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| 160 | ; =================== |
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| 161 | ; |
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| 162 | ; bad = where(abs(glamf-shift(glamf, 0, 1)) LT 1.e-8) |
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| 163 | ; IF bad[0] NE -1 THEN BEGIN |
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| 164 | ; gcosu[bad] = 1. |
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| 165 | ; gsinu[bad] = 0. |
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| 166 | ; ENDIF |
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| 167 | ; bad = where(abs(gphif-shift(gphif, 1, 0)) LT 1.e-8) |
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| 168 | ; IF bad[0] NE -1 THEN BEGIN |
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| 169 | ; gcosv[bad] = 1. |
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| 170 | ; gsinv[bad] = 0. |
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| 171 | ; ENDIF |
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| 172 | ; |
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| 173 | ; III. Lateral boundary conditions |
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| 174 | ; ================================ |
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| 175 | ; |
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| 176 | gcost[*, 0] = gcost[*, 1] |
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| 177 | gsint[*, 0] = gsint[*, 1] |
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| 178 | gcosu[*, 0] = gcosu[*, 1] |
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| 179 | gsinu[*, 0] = gsinu[*, 1] |
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| 180 | gcosv[0, *] = gcosv[jpj-2, *] |
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| 181 | gsinv[0, *] = gsinv[jpj-2, *] |
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| 182 | ; |
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| 183 | RETURN |
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| 184 | END |
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