[59] | 1 | ;+ |
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[232] | 2 | ; |
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[136] | 3 | ; @file_comments |
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[125] | 4 | ; north stereographic polar projection |
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[59] | 5 | ; |
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[231] | 6 | ; @categories |
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[157] | 7 | ; Interpolation |
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| 8 | ; |
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[118] | 9 | ; @param plam {in}{required} |
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[202] | 10 | ; longitude position |
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[59] | 11 | ; |
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[125] | 12 | ; @param pphi {in}{required} |
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[202] | 13 | ; latitude position |
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[118] | 14 | ; |
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[136] | 15 | ; @keyword DOUBLE {default=0} |
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| 16 | ; use double precision (default is float) |
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[118] | 17 | ; |
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[101] | 18 | ; @returns |
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[202] | 19 | ; structure: {x:x, y:y} containing the point position in north stereographic polar projection |
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[59] | 20 | ; |
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[202] | 21 | ; @hidden |
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[59] | 22 | ; |
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| 23 | ;- |
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| 24 | ; |
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| 25 | FUNCTION fsnspp, plam, pphi, DOUBLE = double |
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[114] | 26 | ; |
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| 27 | compile_opt idl2, strictarrsubs |
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| 28 | ; |
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[59] | 29 | IF keyword_set(double) THEN BEGIN |
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| 30 | a = 2.d * tan( !dpi/4.d - !dpi/180.d*pphi/2.d ) |
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| 31 | x = cos( !dpi/180.d*plam ) * a |
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| 32 | y = sin( !dpi/180.d*plam ) * a |
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| 33 | ENDIF ELSE BEGIN |
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| 34 | a = 2. * tan( !pi/4. - !pi/180.*float(pphi)/2. ) |
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| 35 | x = cos( !pi/180.*float(plam) ) * a |
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[125] | 36 | y = sin( !pi/180.*float(plam) ) * a |
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[59] | 37 | ENDELSE |
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| 38 | RETURN, {x:x, y:y} |
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| 39 | END |
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[101] | 40 | ;+ |
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[202] | 41 | ; @file_comments Compute angles between grid lines and direction of the North pole |
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[101] | 42 | ;(fom angle.F,v 2.2 in OPA8.2) |
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| 43 | ; |
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[231] | 44 | ; @categories |
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[202] | 45 | ; Interpolation |
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| 46 | ; |
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| 47 | ; @param fileocemesh {in}{required}{type=scalar string} |
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| 48 | ; a netcdf file that contains (at least) the following variables: |
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[101] | 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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[202] | 53 | ; @param gcosu {out}{type=2d array} |
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| 54 | ; cosinus of the angle between grid lines at U points and direction of the North pole |
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| 55 | ; |
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| 56 | ; @param gsinu {out}{type=2d array} |
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| 57 | ; sinus of the angle between grid lines at U points and direction of the North pole |
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| 58 | ; |
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| 59 | ; @param gcosv {out}{type=2d array} |
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| 60 | ; cosinus of the angle between grid lines at V points and direction of the North pole |
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| 61 | ; |
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| 62 | ; @param gsinv {out}{type=2d array} |
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| 63 | ; sinus of the angle between grid lines at V points and direction of the North pole |
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| 64 | ; |
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| 65 | ; @param gcost {out}{type=2d array} |
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| 66 | ; cosinus of the angle between grid lines at T points and direction of the North pole |
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| 67 | ; |
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| 68 | ; @param gsint {out}{type=2d array} |
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| 69 | ; sinus of the angle between grid lines at T points and direction of the North pole |
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| 70 | ; |
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| 71 | ; @keyword IODIRECTORY {type=scalar string}{default=''} |
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| 72 | ; the directory path where is located fileocemesh |
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| 73 | ; |
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| 74 | ; @keyword DOUBLE {type=1 ou 2}{default=0} |
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| 75 | ; put 1 to use double precision (default is float) |
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| 76 | ; |
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| 77 | ; @restrictions |
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| 78 | ; to compute the lateral boundary conditions, we assume that: |
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| 79 | ; (1) the first line is similar to the second line |
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| 80 | ; => gcosu[*, 0] = gcosu[*, 1] |
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| 81 | ; => gsinu[*, 0] = gsinu[*, 1] |
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| 82 | ; (2) the grid follows OPA x periodicity rule, first column is |
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| 83 | ; equal to the next to last column |
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| 84 | ; => gcosv[0, *] = gcosv[jpj-2, *] |
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| 85 | ; => gsinv[0, *] = gsinv[jpj-2, *] |
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| 86 | ; |
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| 87 | ; @history |
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| 88 | ; Original : 96-07 (O. Marti) |
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| 89 | ; 98-06 (G. Madec) |
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| 90 | ; Feb 2005: IDL adaptation S. Masson |
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| 91 | ; |
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[231] | 92 | ; @version |
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| 93 | ; $Id$ |
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[101] | 94 | ;- |
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[59] | 95 | ; |
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| 96 | PRO angle, fileocemesh, gcosu, gsinu, gcosv, gsinv, gcost, gsint $ |
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| 97 | , IODIRECTORY = iodirectory, DOUBLE = double |
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| 98 | ; |
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| 99 | ; 0. read oceanic grid parameters |
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| 100 | ; ================================ |
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| 101 | ; |
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[114] | 102 | ; |
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| 103 | compile_opt idl2, strictarrsubs |
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| 104 | ; |
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[59] | 105 | IF keyword_set(IODIRECTORY) THEN BEGIN |
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| 106 | IF strpos(iodirectory,'/',/reverse_search) NE (strlen(iodirectory)-1) THEN $ |
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| 107 | iodirectory = iodirectory+'/' |
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| 108 | ENDIF ELSE iodirectory = '' |
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| 109 | fileoce = iodirectory+fileocemesh |
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| 110 | ; |
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| 111 | fileoce = findfile(fileoce, count = okfile) |
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| 112 | IF okfile NE 1 THEN BEGIN |
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[236] | 113 | ras = report('the file '+fileoce+' is not found... we stop') |
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[59] | 114 | stop |
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| 115 | ENDIF |
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| 116 | ; |
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| 117 | cdfido = ncdf_open(fileoce[0]) |
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| 118 | ncdf_varget, cdfido, 'glamt', glamt |
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| 119 | ncdf_varget, cdfido, 'glamu', glamu |
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| 120 | ncdf_varget, cdfido, 'glamv', glamv |
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| 121 | ncdf_varget, cdfido, 'glamf', glamf |
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| 122 | ncdf_varget, cdfido, 'gphit', gphit |
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| 123 | ncdf_varget, cdfido, 'gphiu', gphiu |
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| 124 | ncdf_varget, cdfido, 'gphiv', gphiv |
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| 125 | ncdf_varget, cdfido, 'gphif', gphif |
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| 126 | ncdf_close, cdfido |
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| 127 | ; |
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| 128 | glamt = reform(glamt, /over) |
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| 129 | glamu = reform(glamu, /over) |
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| 130 | glamv = reform(glamv, /over) |
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| 131 | glamf = reform(glamf, /over) |
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| 132 | gphit = reform(gphit, /over) |
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| 133 | gphiu = reform(gphiu, /over) |
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| 134 | gphiv = reform(gphiv, /over) |
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| 135 | gphif = reform(gphif, /over) |
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| 136 | jpj = (size(glamf, /dimension))[1] |
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| 137 | ; |
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| 138 | ; I. Compute the cosinus and sinus |
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| 139 | ; ================================ |
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| 140 | ; (computation done on the north stereographic polar plan |
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| 141 | ; |
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| 142 | ; ... north pole direction & modulous (at t-point) |
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| 143 | znpt = fsnspp( glamt, gphit, DOUBLE = double ) |
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| 144 | glamt = -1 & gphit = -1; free memory |
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| 145 | znpt.x = - znpt.x |
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| 146 | znpt.y = - znpt.y |
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| 147 | znnpt = znpt.x*znpt.x + znpt.y*znpt.y |
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| 148 | ; ... north pole direction & modulous (at u-point) |
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| 149 | znpu = fsnspp( glamu, gphiu, DOUBLE = double ) |
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| 150 | glamu = -1 & gphiu = -1; free memory |
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| 151 | znpu.x = - znpu.x |
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| 152 | znpu.y = - znpu.y |
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| 153 | znnpu = znpu.x*znpu.x + znpu.y*znpu.y |
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| 154 | ; ... north pole direction & modulous (at v-point) |
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| 155 | znpv = fsnspp( glamv, gphiv, DOUBLE = double ) |
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| 156 | znpv00 = znpv |
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| 157 | znpv01 = fsnspp( shift(glamv, 0, 1), shift(gphiv, 0, 1), DOUBLE = double ) |
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| 158 | glamv = -1 & gphiv = -1; free memory |
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| 159 | znpv.x = - znpv.x |
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| 160 | znpv.y = - znpv.y |
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| 161 | znnpv = znpv.x*znpv.x + znpv.y*znpv.y |
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| 162 | ; ... f-point |
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| 163 | znpf00 = fsnspp( glamf, gphif, DOUBLE = double ) |
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| 164 | znpf01 = fsnspp( shift(glamf, 0, 1), shift(gphif, 0, 1), DOUBLE = double ) |
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| 165 | znpf10 = fsnspp( shift(glamf, 1, 0), shift(gphif, 1, 0), DOUBLE = double ) |
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| 166 | glamf = -1 & gphif = -1; free memory |
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| 167 | ; ... j-direction: v-point segment direction (t-point) |
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| 168 | zxvvt = znpv00.x - znpv01.x |
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| 169 | zyvvt = znpv00.y - znpv01.y |
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| 170 | zmnpvt = sqrt ( temporary(znnpt) * ( zxvvt*zxvvt + zyvvt*zyvvt ) ) |
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| 171 | znpv00 = -1; free memory |
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| 172 | znpv01 = -1; free memory |
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| 173 | IF keyword_set(double) THEN zmnpvt = 1.e-14 > zmnpvt $ |
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[125] | 174 | ELSE zmnpvt = 1.e-6 > zmnpvt |
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[59] | 175 | ; ... j-direction: f-point segment direction (u-point) |
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| 176 | zxffu = znpf00.x - znpf01.x |
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| 177 | zyffu = znpf00.y - znpf01.y |
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| 178 | zmnpfu = sqrt ( temporary(znnpu) * ( zxffu*zxffu + zyffu*zyffu ) ) |
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| 179 | znpf01 = -1; free memory |
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| 180 | IF keyword_set(double) THEN zmnpfu = 1.e-14 > zmnpfu $ |
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[125] | 181 | ELSE zmnpfu = 1.e-6 > zmnpfu |
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[59] | 182 | ; ... i-direction: f-point segment direction (v-point) |
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| 183 | zxffv = znpf00.x - znpf10.x |
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[125] | 184 | zyffv = znpf00.y - znpf10.y |
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[59] | 185 | znpf00 = -1 & znpf10 = -1; free memory |
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| 186 | zmnpfv = sqrt ( temporary(znnpv) * ( zxffv*zxffv + zyffv*zyffv ) ) |
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| 187 | IF keyword_set(double) THEN zmnpfv = 1.e-14 > zmnpfv $ |
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[125] | 188 | ELSE zmnpfv = 1.e-6 > zmnpfv |
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[59] | 189 | ; ... cosinus and sinus using scalar and vectorial products |
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| 190 | gsint = ( znpt.x*zyvvt - znpt.y*zxvvt ) / zmnpvt |
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| 191 | gcost = ( znpt.x*zxvvt + znpt.y*zyvvt ) / zmnpvt |
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| 192 | ; ... cosinus and sinus using scalar and vectorial products |
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| 193 | gsinu = ( znpu.x*zyffu - znpu.y*zxffu ) / zmnpfu |
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| 194 | gcosu = ( znpu.x*zxffu + znpu.y*zyffu ) / zmnpfu |
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| 195 | ; ... cosinus and sinus using scalar and vectorial products |
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| 196 | ; (caution, rotation of 90 degres) |
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| 197 | gsinv = ( znpv.x*zxffv + znpv.y*zyffv ) / zmnpfv |
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| 198 | gcosv = -( znpv.x*zyffv - znpv.y*zxffv ) / zmnpfv |
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| 199 | ; |
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| 200 | ; II. Geographic mesh |
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| 201 | ; =================== |
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| 202 | ; |
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| 203 | ; bad = where(abs(glamf-shift(glamf, 0, 1)) LT 1.e-8) |
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| 204 | ; IF bad[0] NE -1 THEN BEGIN |
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| 205 | ; gcosu[bad] = 1. |
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| 206 | ; gsinu[bad] = 0. |
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| 207 | ; ENDIF |
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| 208 | ; bad = where(abs(gphif-shift(gphif, 1, 0)) LT 1.e-8) |
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| 209 | ; IF bad[0] NE -1 THEN BEGIN |
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| 210 | ; gcosv[bad] = 1. |
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| 211 | ; gsinv[bad] = 0. |
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| 212 | ; ENDIF |
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| 213 | ; |
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| 214 | ; III. Lateral boundary conditions |
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| 215 | ; ================================ |
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| 216 | ; |
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[125] | 217 | gcost[*, 0] = gcost[*, 1] |
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| 218 | gsint[*, 0] = gsint[*, 1] |
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| 219 | gcosu[*, 0] = gcosu[*, 1] |
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| 220 | gsinu[*, 0] = gsinu[*, 1] |
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[59] | 221 | gcosv[0, *] = gcosv[jpj-2, *] |
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| 222 | gsinv[0, *] = gsinv[jpj-2, *] |
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| 223 | ; |
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| 224 | RETURN |
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| 225 | END |
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