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