source: trunk/SRC/ReadWrite/read_grads.pro @ 107

Last change on this file since 107 was 106, checked in by pinsard, 18 years ago

start to modify headers of ReadWrite? *.pro files for better idldoc output
  • Property svn:executable set to *
File size: 11.5 KB
Line 
1;------------------------------------------------------------
2;------------------------------------------------------------
3;------------------------------------------------------------
4;+
5; @file_comments reading grads file (except "data type station" or "grib")
6; from the grads control file even if there is multiple data files.
7;
8; @categories reading function
9;
10;       @param var {in}{required} the variable name
11;       @param date1 {in}{required} date of the beginning (yyyymmdd if TIMESTEP is not activate)
12;       @param date2 {in}{optional} last date. Optionnal, if not scpecified date2=date1
13;     
14; @keyword FILENAME the grads control file name: 'xxxx.ctl'
15;
16; @file_comments keyword GLAMBOUNDARY (via computegrid.pro) a 2 elements vector,
17;       {lon1,lon2], giving the longitute boundaries that should be
18;       used to visualize the data.
19;         lon2 > lon1
20;         lon2 - lon1 eq 360
21;       key_shift will be automatically defined according to
22;       GLAMBOUNDARY.
23;
24;       @keyword /TIMESTEP to specify that the dates are time steps instead of
25;       true calendar.
26;
27;        @file_comments keyword IODIRECTORY a string giving the name of iodirectory (see
28;       isafile.pro for all possibilities). default value is common
29;       variable iodir
30;
31; @file_comments
32;---------------
33; NOT yet available
34;---------------
35;
36;       @hidden BOX: a 4 or 6 elements 1d array, [lon1,lon2,lat1,lat2, depth1,
37;       depth2], that specifies the area where data must be read
38;
39;       @hidden EVERYTHING
40;
41;       @hidden NOSTRUCTURE
42;       
43; @returns an array
44;
45; @uses common
46;
47; @restriction define all the grid parameters (defined in common.pro)
48; associated to the data.
49;
50; @restrictions this function call the procedure scanfile that use the
51; unix commands grep and sed
52;
53; @examples
54;    IDL> a=read_grads('sst',19900101,19900131,filename='outputs.ctl')
55;    IDL> plt, a
56;
57; @history Sebastien Masson (smasson\@lodyc.jussieu.fr)
58;
59;-
60;------------------------------------------------------------
61;------------------------------------------------------------
62;------------------------------------------------------------
63
64FUNCTION read_grads, var, date1, date2, FILENAME = filename, BOX=box, TIMESTEP = timestep, EVERYTHING = everything, NOSTRUCT = nostruct, _EXTRA = ex
65;---------------------------------------------------------
66@cm_4mesh
67@cm_4data
68@cm_4cal
69  IF NOT keyword_set(key_forgetold) THEN BEGIN
70@updatenew
71  ENDIF
72;------------------------------------------------------------
73; we find the filename.
74;------------------------------------------------------------
75   filename = isafile(FILENAME = filename, IODIRECTORY = iodir, _EXTRA = ex)
76   if size(filename, /type) NE 7 then $
77    return, report('read_ncdf cancelled')
78;------------------------------------------------------------
79; we scan the control file called filename
80;------------------------------------------------------------
81   scanctl, filename, filesname, jpt1file, varsname, varslev, swapbytes, bigendian, littleendian, f77sequential, fileheader, theader, xyheader, VARFMT = varfmt, _EXTRA = ex
82   if n_elements(varfmt) EQ 0 then varfmt = 'float'
83;------------------------
84;------------------------
85; check date1 and date2 and found the starting index "t1" and the
86; ending index "t2" that corresponds to the time series specified by
87; date1 and date2 for the time axis defined in the .ctl file.
88;------------------------
89;------------------------
90   if n_elements(date1) EQ 0 then begin
91      t0 = 0
92      t1 = 0
93   ENDIF
94   if n_elements(date2) EQ 0 then date2 = date1
95   if keyword_set(timestep) then BEGIN
96      if date1 GT date2 then begin
97         print, 'date2 must be larger than date1'
98         return, -1
99      endif
100      t1 = 0 > long(date1) < (jpt-1)
101      t2 = t1 > long(date2) < (jpt-1)
102   ENDIF ELSE BEGIN
103      jdate1 = date2jul(date1, /grads) < time[jpt-1]
104      jdate2 = time[0] > date2jul(date2, /grads)
105      if jdate1 GT jdate2 then begin
106         print, 'date2 must be larger than date1'
107         return, -1
108      endif
109      t1 = (where(time GE jdate1))[0]
110      tmp = where(time LE jdate2, t2)
111      t2 = t2-1
112   ENDELSE
113   if t2 LT t1 then begin
114      print, 'There is no date between date1 and date2'
115      return, -1
116   endif
117   jpt2read = t2-t1+1
118;------------------------
119;------------------------
120; index of the variable
121;------------------------
122;------------------------
123   varid = where(strlowcase(varsname) EQ strlowcase(var))
124   varid = varid[0]
125   if varid EQ -1 then begin
126      print, var+' not found in the variable liste of '+filename
127      return,  -1
128   ENDIF
129   varname = var
130   if varslev[varid] EQ 1 then res = fltarr(jpi, jpj, jpt2read, /nozero) $
131   ELSE res = fltarr(jpi, jpj, varslev[varid], jpt2read, /nozero)
132;------------------------
133;------------------------
134; find the first file to be read according to the lile list,, the
135; number of time step in each file and t1 and t2
136;------------------------
137;------------------------
138   indf2read = t1/jpt1file
139   startread = t1-indf2read*jpt1file
140   alreadyread = 0
141readagain:
142   jpt2read1file = min([jpt1file-startread, jpt2read])
143   f2read = filesname[indf2read]
144;------------------------
145;------------------------
146; opening
147;------------------------
148;------------------------;
149; check the existance of the file
150   f2read = isafile(filename = f2read, iodirectory = iodir, _EXTRA = ex)
151; if the file is stored on tape
152   if !version.os_family EQ 'unix' then spawn, 'file '+f2read+' > /dev/null'
153; open the file
154   openr, unit, f2read, /get_lun, error=err $
155    , swap_if_little_endian = bigendian $
156    , swap_if_big_endian = littleendian $
157    , swap_endian = swapbytes
158   if err ne 0 then begin
159      print,!err_string
160      return, -1
161   endif
162;------------------------
163   case varfmt of
164      'byte':fmtsz = 1l
165      'uint':fmtsz = 2l
166      'int':fmtsz = 2l
167      'long':fmtsz = 4l
168      'float':fmtsz = 4l
169   endcase
170;------------------------
171; check its size
172   addf77sec = long(4*2*f77sequential)
173   xyblocsize = xyheader + addf77sec*(xyheader NE 0) + jpi*jpj*fmtsz +addf77sec
174   nxybloc = long(total(varslev))
175   filesize = (fileheader + addf77sec*(fileheader NE 0)) $
176    +(theader+addf77sec*(theader NE 0) + nxybloc*xyblocsize)*jpt1file
177   infof2read=fstat(unit)
178   if infof2read.size NE filesize then begin
179      print, 'According to '+filename+' the file size must be '+strtrim(filesize, 1)+' instead of '+strtrim(infof2read.size, 1)
180      print, 'jpi: '+strtrim(jpi, 2)
181      print, 'jpj: '+strtrim(jpj, 2)
182      print, 'jpt: '+strtrim(jpt, 2)
183      print, 'format size in byte: '+strtrim(fmtsz, 2)
184      print, 'number of xy arrays: '+strtrim(nxybloc, 2)
185      return, -1
186   endif
187;------------------------
188;------------------------
189; reading
190;------------------------
191;------------------------;
192;------------------------;
193; loop on the time steps to be read in one file
194   for i = 0, jpt2read1file-1 do begin
195; computing the offset
196      offset = (fileheader + addf77sec*(fileheader NE 0)) $
197       +(theader+addf77sec*(theader NE 0) + nxybloc*xyblocsize)*(startread+i) $
198       +theader+addf77sec*(theader NE 0)
199      if varid NE 0 THEN $
200       offset = offset + long(total(varslev[0:varid-1]))*xyblocsize
201; if there is only one level
202      IF varslev[varid] EQ 1 then begin
203         case varfmt of
204            'byte':a=assoc(unit, bytarr(jpi,jpj,/nozero), offset+4*f77sequential)
205            'uint':a=assoc(unit,uintarr(jpi,jpj,/nozero), offset+4*f77sequential)
206            'int':a=assoc(unit,  intarr(jpi,jpj,/nozero), offset+4*f77sequential)
207            'long':a=assoc(unit, lonarr(jpi,jpj,/nozero), offset+4*f77sequential)
208            'float':a=assoc(unit,fltarr(jpi,jpj,/nozero), offset+4*f77sequential)
209         endcase
210         res[*, *, i+alreadyread]=a[0]
211      ENDIF ELSE BEGIN ; more than 1 level to be read
212         if f77sequential then BEGIN ; sequential access
213            case varfmt of
214               'byte':a=assoc(unit, bytarr(jpi*jpj+8, varslev[varid],/nozero), offset)
215               'uint':a=assoc(unit,uintarr(jpi*jpj+4, varslev[varid],/nozero), offset)
216               'int':a=assoc(unit,  intarr(jpi*jpj+4, varslev[varid],/nozero), offset)
217               'long':a=assoc(unit, lonarr(jpi*jpj+2, varslev[varid],/nozero), offset)
218               'float':a=assoc(unit,fltarr(jpi*jpj+2, varslev[varid],/nozero), offset)
219            endcase
220            tmp = a[0]
221            case varfmt OF ; we cut the headers and tailers of f77 write
222               'byte': tmp = tmp[4:jpi*jpj+3, *]
223               'uint': tmp = tmp[2:jpi*jpj+1, *]
224               'int':  tmp = tmp[2:jpi*jpj+1, *]
225               'long': tmp = tmp[1:jpi*jpj+0, *]
226               'float':tmp = tmp[1:jpi*jpj+0, *]
227            endcase
228            if keyword_set(key_zreverse) then res[*, *, *, i+alreadyread]=reverse(reform(tmp,  jpi, jpj, varslev[varid], /over), 3) ELSE res[*, *, *, i+alreadyread]=reform(tmp,  jpi, jpj, varslev[varid], /over)
229         ENDIF ELSE BEGIN  ; direct acces
230            case varfmt of
231               'byte':a=assoc(unit, bytarr(jpi,jpj,varslev[varid],/nozero),offset)
232               'uint':a=assoc(unit,uintarr(jpi,jpj,varslev[varid],/nozero),offset)
233               'int':a=assoc(unit,  intarr(jpi,jpj,varslev[varid],/nozero),offset)
234               'long':a=assoc(unit, lonarr(jpi,jpj,varslev[varid],/nozero),offset)
235               'float':a=assoc(unit,fltarr(jpi,jpj,varslev[varid],/nozero),offset)
236            endcase
237            if keyword_set(key_zreverse) then res[*, *, *, i+alreadyread]=reverse(a[0], 3) ELSE res[*, *, *, i+alreadyread]=a[0]
238         ENDELSE
239      ENDELSE
240   endfor
241;------------------------
242; close the file
243   free_lun,unit
244   close,unit
245;------------------------
246;------------------------
247; do we need to read a new file to complete the time series ?
248;------------------------
249;------------------------
250   if jpt2read1file NE jpt2read then BEGIN
251      indf2read = indf2read+1
252      startread = 0
253      alreadyread = alreadyread+jpt2read1file
254      jpt2read = jpt2read-jpt2read1file
255      GOTO, readagain
256   ENDIF
257;------------------------
258;------------------------
259; post processing
260;------------------------
261;------------------------
262   if keyword_set(key_yreverse) then res = reverse(res, 2)
263   if keyword_set(key_shift) then begin
264      case (size(res))[0] of
265         2:res = shift(res, key_shift, 0)
266         3:res = shift(res, key_shift, 0, 0)
267         4:res = shift(res, key_shift, 0, 0, 0)
268      endcase
269   endif
270;------------------------
271;   mask
272;   IF varslev[varid] EQ 1 then begin
273;      if abs(valmask) LE 1e5 then notgood = where(res[*, *, 0] EQ valmask) $
274;      ELSE notgood = where(abs(res[*, *, 0]) GE abs(valmask)/10)
275;      if notgood[0] NE -1 then tmask[notgood] = 0b
276;   ENDIF ELSE BEGIN
277;      if abs(valmask) LE 1e5 then notgood = where(res[*, *, *, 0] EQ valmask) $
278;      ELSE notgood = where(abs(res[*, *, *, 0]) GE abs(valmask)/10)
279;      if notgood[0] NE -1 then tmask[notgood] = 0b
280;   ENDELSE
281   if abs(valmask) LE 1e5 then notgood = where(res EQ valmask) $
282   ELSE notgood = where(abs(res) GE abs(valmask)/10)
283   if notgood[0] NE -1 THEN res[notgood] = !values.f_nan
284;   valmask = 1e20
285;   if abs(valmask) LE 1e5 then notgood = where(res EQ valmask) $
286;   ELSE notgood = where(abs(res) GE abs(valmask)/10)
287;   if notgood[0] NE -1 THEN res[notgood] = 1e20
288;   valmask = 1e20
289   triangles_list = triangule()
290;------------------------
291; subdomain extration
292
293;------------------------
294; time aguments
295;------------------------
296   time = time[t1:t2]
297   jpt = t2-t1+1
298   if keyword_set(timestep) then vardate = strtrim(time[0], 2) $
299   ELSE vardate = date2string(vairdate(time[0]))
300;------------------------
301   @updateold
302;------------------------
303
304   return, res
305end
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