[2] | 1 | ; $Id$ |
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| 2 | ; |
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| 3 | ; Copyright (c) 1992-1998, Research Systems, Inc. All rights reserved. |
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| 4 | ; Unauthorized reproduction prohibited. |
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| 5 | ; |
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| 6 | |
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| 7 | ;+ |
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| 8 | ; NAME: |
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| 9 | ; CALDAT |
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| 10 | ; |
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| 11 | ; PURPOSE: |
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| 12 | ; Return the calendar date and time given julian date. |
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| 13 | ; This is the inverse of the function JULDAY. |
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| 14 | ; CATEGORY: |
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| 15 | ; Misc. |
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| 16 | ; |
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| 17 | ; CALLING SEQUENCE: |
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| 18 | ; CALDAT, Julian, Month, Day, Year, Hour, Minute, Second |
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| 19 | ; See also: julday, the inverse of this function. |
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| 20 | ; |
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| 21 | ; INPUTS: |
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| 22 | ; JULIAN contains the Julian Day Number (which begins at noon) of the |
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| 23 | ; specified calendar date. It should be a long integer. |
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| 24 | ; |
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| 25 | ; KEYWORD PARAMETERS: |
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| 26 | ; |
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| 27 | ; NDAYSPM: developpe par eric, ca veut dire: nombre de jours par mois! |
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| 28 | ; par defaut c''est 30, sinon le specifier en donnant |
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| 29 | ; une valeur a ndayspm |
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| 30 | ; pour passer a un calendrier avec un nombre de jours constant par |
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| 31 | ; mois. Utilise en particulier ds julday et caldat |
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| 32 | ; |
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| 33 | ; OUTPUTS: |
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| 34 | ; (Trailing parameters may be omitted if not required.) |
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| 35 | ; MONTH: Number of the desired month (1 = January, ..., 12 = December). |
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| 36 | ; |
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| 37 | ; DAY: Number of day of the month. |
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| 38 | ; |
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| 39 | ; YEAR: Number of the desired year. |
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| 40 | ; |
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| 41 | ; HOUR: Hour of the day |
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| 42 | ; Minute: Minute of the day |
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| 43 | ; Second: Second (and fractions) of the day. |
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| 44 | ; |
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| 45 | ; COMMON BLOCKS: |
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| 46 | ; None. |
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| 47 | ; |
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| 48 | ; SIDE EFFECTS: |
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| 49 | ; None. |
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| 50 | ; |
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| 51 | ; RESTRICTIONS: |
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| 52 | ; Accuracy using IEEE double precision numbers is approximately |
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| 53 | ; 1/10000th of a second. |
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| 54 | ; |
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| 55 | ; MODIFICATION HISTORY: |
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| 56 | ; Translated from "Numerical Recipies in C", by William H. Press, |
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| 57 | ; Brian P. Flannery, Saul A. Teukolsky, and William T. Vetterling. |
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| 58 | ; Cambridge University Press, 1988 (second printing). |
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| 59 | ; |
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| 60 | ; DMS, July 1992. |
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| 61 | ; DMS, April 1996, Added HOUR, MINUTE and SECOND keyword |
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| 62 | ; AB, 7 December 1997, Generalized to handle array input. |
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| 63 | ; Eric Guilyardi, June 1999 |
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| 64 | ; Added key_work ndayspm for fixed number of days per months |
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| 65 | ;- |
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| 66 | ; |
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| 67 | |
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| 68 | |
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| 69 | pro caldat_scalar, Julian, Month, Day, Year, Hour, Minute, Second, NDAYSPM = ndayspm |
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| 70 | ; Internal variant of CALDAT that does the actual work on a single |
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| 71 | ; value. |
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| 72 | |
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| 73 | ON_ERROR, 2 ; Return to caller if errors |
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| 74 | |
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| 75 | IF NOT keyword_set(ndayspm) THEN BEGIN |
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| 76 | |
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| 77 | IGREG = 2299161L ;Beginning of Gregorian calendar |
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| 78 | |
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| 79 | IF julian GE 0 THEN jul = long(julian + .5d) $ ;Better be long |
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| 80 | ELSE jul = long(julian - .5d) |
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| 81 | f = julian + .5d - jul |
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| 82 | if f ne 0.0 then begin ;Get hours, minutes, seconds. |
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| 83 | hour = floor(f * 24.) |
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| 84 | f = f - hour / 24.d |
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| 85 | minute = floor(f*1440) |
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| 86 | second = (f - minute/1440.d0) * 86400.0d0 |
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| 87 | endif else begin |
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| 88 | hour = 0L |
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| 89 | minute = 0L |
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| 90 | second = 0L |
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| 91 | endelse |
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| 92 | |
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| 93 | |
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| 94 | if jul ge igreg then begin |
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| 95 | jalpha = long(((jul - 1867216) - 0.25d0) / 36524.25) |
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| 96 | ja = jul + 1 + jalpha - long(0.25d0 * jalpha) |
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| 97 | endif else ja = jul |
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| 98 | |
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| 99 | jb = ja + 1524l |
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| 100 | jc = long(6680.0 + ((jb-2439870)-122.1d0)/365.25) |
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| 101 | jd = long(365 * jc + (0.25 * jc)) |
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| 102 | je = long((jb - jd) / 30.6001) |
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| 103 | |
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| 104 | day = jb - jd - long(30.6001d * je) |
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| 105 | month = je -1 |
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| 106 | if (month gt 12) then month = month - 12 |
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| 107 | year = jc - 4715 |
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| 108 | if month gt 2 then year = year - 1 |
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| 109 | if year le 0 then year = year - 1 |
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| 110 | |
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| 111 | ENDIF ELSE BEGIN |
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| 112 | |
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| 113 | jul = long(julian) |
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| 114 | f = (jul - floor(jul)) |
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| 115 | IF f NE 0.0 THEN BEGIN ;Get hours, minutes, seconds. |
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| 116 | hour = floor(f*24.) |
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| 117 | f = f - hour / 24.d |
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| 118 | minute = floor(f*1440) |
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| 119 | second = (f - minute/1440.d0) * 86400.0d0 |
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| 120 | ENDIF ELSE BEGIN |
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| 121 | hour = 0L |
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| 122 | minute = 0L |
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| 123 | second = 0L |
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| 124 | ENDELSE |
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| 125 | |
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| 126 | IF ndayspm EQ 1 THEN ndayspm = 30 |
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| 127 | |
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| 128 | Z = floor(julian) |
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| 129 | X = Z / ndayspm |
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| 130 | day = Z - X*ndayspm |
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| 131 | year = X / 12 |
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| 132 | month = X - year*12 + 1 |
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| 133 | year = year + 1 |
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| 134 | |
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| 135 | ENDELSE |
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| 136 | |
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| 137 | end |
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| 138 | |
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| 139 | |
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| 140 | |
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| 141 | |
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| 142 | pro caldat, Julian, Month, Day, Year, Hour, Minute, Second, NDAYSPM = ndayspm |
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| 143 | |
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| 144 | ON_ERROR, 2 ; Return to caller if errors |
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| 145 | |
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| 146 | ; Determine shape of input and construct longword output variables of |
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| 147 | ; the same shape. |
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| 148 | |
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| 149 | s = size(julian) |
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| 150 | if (s[0] eq 0) then begin |
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| 151 | ; Julian is scalar. Just call CALDAT_SCALAR and pass our arguments through. |
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| 152 | caldat_scalar, Julian, Month, Day, Year, Hour, Minute, Second, NDAYSPM = ndayspm |
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| 153 | return |
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| 154 | endif |
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| 155 | |
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| 156 | ; It's an array. Construct result variables |
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| 157 | ndim = s[0] ; Number or array dimensions |
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| 158 | n = s[ndim + 2] ; # of elements |
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| 159 | s[ndim + 1] = 3 ; Change the type to LONG |
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| 160 | MONTH = (DAY = (YEAR = (HOUR = (MINUTE = (SECOND = MAKE_ARRAY(SIZE=s)))))) |
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| 161 | |
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| 162 | ; Loop over the input |
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| 163 | for i = 0, n-1 do begin |
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| 164 | caldat_scalar, julian[i], month_tmp, day_tmp, year_tmp, $ |
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| 165 | hour_tmp, minute_tmp, second_tmp, NDAYSPM = ndayspm |
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| 166 | month[i] = month_tmp |
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| 167 | day[i] = day_tmp |
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| 168 | year[i] = year_tmp |
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| 169 | hour[i] = hour_tmp |
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| 170 | minute[i] = minute_tmp |
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| 171 | second[i] = second_tmp |
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| 172 | endfor |
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| 173 | end |
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