[110] | 1 | ;+ |
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| 2 | ; |
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[136] | 3 | ; @file_comments |
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[125] | 4 | ; interpolate data from an irregular 2D grid to any 2D grid. |
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| 5 | ; Only 1 method available = bilinear |
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| 6 | ; |
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[157] | 7 | ; @categories |
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| 8 | ; Interpolation |
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[110] | 9 | ; |
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[163] | 10 | ; @param method {in}{required}{type=string} |
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[136] | 11 | ; a string defining the interpolation method. must be 'bilinear' |
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[110] | 12 | ; |
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[163] | 13 | ; @param datain {in}{required}{type=2d array} |
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[136] | 14 | ; a 2D array the input data to interpolate |
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| 15 | ; |
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[205] | 16 | ; @param lonin {in}{required}{type=2d array} |
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[136] | 17 | ; a 2D array defining the longitude of the input data |
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| 18 | ; |
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[205] | 19 | ; @param latin {in}{required}{type=2d array} |
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[136] | 20 | ; a 2D array defining the latitude of the input data. |
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| 21 | ; |
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[205] | 22 | ; @param mskin {in}{required}{type=2d array or -1} |
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[136] | 23 | ; a 2D array, the land-sea mask of the input data (1 on ocean, 0 on land) |
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[202] | 24 | ; put -1 if input data are not masked |
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[136] | 25 | ; |
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[205] | 26 | ; @param lonout {in}{required}{type=1d or 2d array} |
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[136] | 27 | ; 1D or 2D array defining the longitude of the output data. |
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| 28 | ; |
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[205] | 29 | ; @param latout {in}{required}{type=1d or 2d array} |
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[136] | 30 | ; 1D or 2D array defining the latitude of the output data. |
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| 31 | ; |
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[202] | 32 | ; @param mskout {in}{required}{type=2d array or -1} |
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[163] | 33 | ; a 2D array, the land-sea mask of the output data (1 on ocean, 0 on land) |
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[202] | 34 | ; put -1 if output data are not masked |
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[136] | 35 | ; |
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[163] | 36 | ; @keyword WEIG {type=2d array} |
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| 37 | ; (see ADDR) |
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| 38 | ; |
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| 39 | ; @keyword ADDR {type=2d array} |
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| 40 | ; 2D arrays, weig and addr are the weight and addresses used to |
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[136] | 41 | ; perform the interpolation: |
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[110] | 42 | ; dataout = total(weig*datain[addr], 1) |
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| 43 | ; dataout = reform(dataout, jpio, jpjo, /over) |
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[136] | 44 | ; Those keywords can be set to named variables (that are undefined or equal to 0) into which the |
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| 45 | ; values will be copied when the current routine exits. Next, they can be used to perform |
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[163] | 46 | ; the interpolation without computing again those 2 parameters. This greatly |
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[136] | 47 | ; speed-up the interpolation! In that case, lonin, latin, lonout and latout are not necessary. |
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[110] | 48 | ; |
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[136] | 49 | ; @returns |
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| 50 | ; 2D array the interpolated data |
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[110] | 51 | ; |
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[125] | 52 | ; @restrictions |
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| 53 | ; We supposed the data are located on a sphere, with a periodicity along |
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| 54 | ; the longitude. |
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| 55 | ; Note that the input data can contain the same cells several times |
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| 56 | ; (like ORCA grid near the north pole boundary) |
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[110] | 57 | ; |
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| 58 | ; @examples |
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[125] | 59 | ; |
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[118] | 60 | ; IDL> tncep = fromirr('bilinear', topa, glamt, gphit, tmask[*,*,0], lonout, latout, mskout) |
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[110] | 61 | ; |
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[125] | 62 | ; or |
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[110] | 63 | ; |
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[118] | 64 | ; IDL> t1ncep = fromirr('bilinear', topa, glamt, gphit, tmask[*,*,0], lonout, latout, mskout $ |
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[110] | 65 | ; , WEIG = a, ADDR = b) |
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[118] | 66 | ; IDL> help, a, b |
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| 67 | ; IDL> t2ncep = fromirr('bilinear', topa, WEIG = a, ADDR = b) |
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[110] | 68 | ; |
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| 69 | ; @history |
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[125] | 70 | ; June 2006: Sebastien Masson (smasson\@lodyc.jussieu.fr) |
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| 71 | ; |
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[118] | 72 | ; @version $Id$ |
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| 73 | ; |
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[110] | 74 | ;- |
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| 75 | ;---------------------------------------------------------- |
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| 76 | ;---------------------------------------------------------- |
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| 77 | ; |
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| 78 | FUNCTION fromirr, method, datain, lonin, latin, mskin, lonout, latout, mskout $ |
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| 79 | , WEIG = weig, ADDR = addr |
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| 80 | ; |
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[125] | 81 | compile_opt strictarr, strictarrsubs |
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[110] | 82 | ; |
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| 83 | ;--------------- |
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| 84 | ; atmospheric grid parameters |
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| 85 | ;--------------- |
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| 86 | alon = lonin |
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| 87 | alat = latin |
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| 88 | get_gridparams, alon, alat, jpia, jpja, 2, /double |
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| 89 | ;--------------- |
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| 90 | ; Oceanic grid parameters |
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| 91 | ;--------------- |
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| 92 | olon = lonout |
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| 93 | olat = latout |
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| 94 | get_gridparams, olon, olat, jpio, jpjo, 2, /double |
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| 95 | ;--------------- |
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| 96 | ; Compute weight and address |
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| 97 | ;--------------- |
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[113] | 98 | IF NOT (keyword_set(weig) AND keyword_set(addr)) THEN BEGIN |
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[110] | 99 | CASE method OF |
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| 100 | 'bilinear':compute_fromirr_bilinear_weigaddr, alon, alat, mskin, olon, olat, mskout, weig, addr |
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[125] | 101 | ELSE:BEGIN |
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[110] | 102 | print, ' unknown interpolation method... we stop' |
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| 103 | stop |
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| 104 | ENDELSE |
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| 105 | ENDCASE |
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| 106 | ENDIF |
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| 107 | ;--------------- |
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| 108 | ; to the interpolation |
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| 109 | ;--------------- |
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| 110 | dataout = total(weig*datain[addr], 1) |
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| 111 | dataout = reform(dataout, jpio, jpjo, /over) |
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| 112 | ; |
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| 113 | RETURN, dataout |
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| 114 | END |
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