source: trunk/python/scantable.py@ 262

Last change on this file since 262 was 256, checked in by mar637, 20 years ago
  • rewrote save to avoid using empty filenames
  • rewrote stat,tsys output and formatting
  • renmaing of function names
  • Property svn:eol-style set to native
  • Property svn:keywords set to Author Date Id Revision
File size: 20.7 KB
Line 
1from asap._asap import sdtable
2from asap import rcParams
3from numarray import ones,zeros
4import sys
5
6class scantable(sdtable):
7 """
8 The ASAP container for scans
9 """
10
11 def __init__(self, filename):
12 """
13 Create a scantable from a saved one or make a reference
14 Parameters:
15 filename: the name of an asap table on disk
16 or
17 the name of a rpfits/sdfits/ms file
18 (integrations within scans are auto averaged
19 and the whole file is read)
20 or
21 [advanced] a reference to an existing
22 scantable
23 """
24 self._vb = rcParams['verbose']
25 self._p = None
26 from os import stat as st
27 import stat
28 if isinstance(filename,sdtable):
29 sdtable.__init__(self, filename)
30 else:
31 try:
32 mode = st(filename)[stat.ST_MODE]
33 except OSError:
34 print "File not found"
35 return
36 if stat.S_ISDIR(mode):
37 # crude check if asap table
38 if stat.S_ISREG(st(filename+'/table.info')[stat.ST_MODE]):
39 sdtable.__init__(self, filename)
40 else:
41 print 'The given file is not a valid asap table'
42 return
43 else:
44 autoav = rcParams['scantable.autoaverage']
45
46 from asap._asap import sdreader
47 r = sdreader(filename)
48 print 'Importing data...'
49 r.read([-1])
50 tbl = r.getdata()
51 if autoav:
52 from asap._asap import average
53 tmp = tuple([tbl])
54 print 'Auto averaging integrations...'
55 tbl2 = average(tmp,(),True,'none')
56 sdtable.__init__(self,tbl2)
57 del r,tbl
58 else:
59 sdtable.__init__(self,tbl)
60
61 def save(self, name=None, format=None, overwrite=False):
62 """
63 Store the scantable on disk. This can be a asap file or SDFITS/MS2.
64 Parameters:
65 name: the name of the outputfile. For format="FITS" this
66 is the root file name (and can be empty).
67 format: an optional file format. Default is ASAP.
68 Allowed are - 'ASAP' (save as ASAP Table),
69 'SDFITS' (save as SDFITS file)
70 'FITS' (saves each row as a FITS Image)
71 'ASCII' (saves as ascii text file)
72 'MS2' (saves as an aips++
73 MeasurementSet V2)
74 overwrite: if the file should be overwritten if it exists.
75 The default False is to return with warning
76 without writing the output
77 Example:
78 scan.save('myscan.asap')
79 scan.save('myscan.sdfits','SDFITS')
80 """
81 if format is None: format = rcParams['scantable.save']
82 suffix = '.'+format.lower()
83 if name is None or name =="":
84 name = 'scantable'+suffix
85 from os import path
86 if path.isfile(name) or path.isdir(name):
87 if not overwrite:
88 print "File %s already exists." % name
89 return
90 if format == 'ASAP':
91 self._save(name)
92 else:
93 from asap._asap import sdwriter as _sw
94 w = _sw(format)
95 w.write(self, name)
96 return
97
98 def copy(self):
99 """
100 Return a copy of this scantable.
101 Parameters:
102 none
103 Example:
104 copiedscan = scan.copy()
105 """
106 sd = scantable(sdtable._copy(self))
107 return sd
108
109 def get_scan(self, scanid=None):
110 """
111 Return a specific scan (by scanno) or collection of scans (by
112 source name) in a new scantable.
113 Parameters:
114 scanid: a scanno or a source name
115 Example:
116 scan.get_scan('323p459')
117 # gets all scans containing the source '323p459'
118 """
119 if scanid is None:
120 print "Please specify a scan no or name to retrieve from the scantable"
121 try:
122 if type(scanid) is str:
123 s = sdtable._getsource(self,scanid)
124 return scantable(s)
125 elif type(scanid) is int:
126 s = sdtable._getscan(self,scanid)
127 return scantable(s)
128 except RuntimeError:
129 print "Couldn't find any match."
130
131 def __str__(self):
132 return sdtable._summary(self)
133
134 def summary(self,filename=None):
135 """
136 Print a summary of the contents of this scantable.
137 Parameters:
138 filename: the name of a file to write the putput to
139 Default - no file output
140 """
141 info = sdtable._summary(self)
142 if filename is not None:
143 if filename is "":
144 filename = 'scantable_summary.txt'
145 data = open(filename, 'w')
146 data.write(info)
147 data.close()
148 print info
149
150 def set_cursor(self, thebeam=0,theif=0,thepol=0):
151 """
152 Set the spectrum for individual operations.
153 Parameters:
154 thebeam,theif,thepol: a number
155 Example:
156 scan.set_cursor(0,0,1)
157 pol1sig = scan.stats(all=False) # returns std dev for beam=0
158 # if=0, pol=1
159 """
160 self.setbeam(thebeam)
161 self.setpol(thepol)
162 self.setif(theif)
163 return
164
165 def get_cursor(self):
166 """
167 Return/print a the current 'cursor' into the Beam/IF/Pol cube.
168 Parameters:
169 none
170 Returns:
171 a list of values (currentBeam,currentIF,currentPol)
172 Example:
173 none
174 """
175 i = self.getbeam()
176 j = self.getif()
177 k = self.getpol()
178 if self._vb:
179 print "--------------------------------------------------"
180 print " Cursor position"
181 print "--------------------------------------------------"
182 out = 'Beam=%d IF=%d Pol=%d ' % (i,j,k)
183 print out
184 return i,j,k
185
186 def stats(self, stat='stddev', mask=None, all=None):
187 """
188 Determine the specified statistic of the current beam/if/pol
189 Takes a 'mask' as an optional parameter to specify which
190 channels should be excluded.
191 Parameters:
192 stat: 'min', 'max', 'sumsq', 'sum', 'mean'
193 'var', 'stddev', 'avdev', 'rms', 'median'
194 mask: an optional mask specifying where the statistic
195 should be determined.
196 all: if true show all (default or .asaprc) rather
197 that the cursor selected spectrum of Beam/IF/Pol
198
199 Example:
200 scan.set_unit('channel')
201 msk = scan.create_mask([100,200],[500,600])
202 scan.stats(stat='mean', mask=m)
203 """
204 if all is None: all = rcParams['scantable.allaxes']
205 from asap._asap import stats as _stats
206 from numarray import array,zeros,Float
207 if mask == None:
208 mask = ones(self.nchan())
209 axes = ['Beam','IF','Pol','Time']
210
211 if all:
212 n = self.nbeam()*self.nif()*self.npol()*self.nrow()
213 shp = [self.nbeam(),self.nif(),self.npol(),self.nrow()]
214 arr = array(zeros(n),shape=shp,type=Float)
215
216 for i in range(self.nbeam()):
217 self.setbeam(i)
218 for j in range(self.nif()):
219 self.setif(j)
220 for k in range(self.npol()):
221 self.setpol(k)
222 arr[i,j,k,:] = _stats(self,mask,stat,-1)
223 retval = {'axes': axes, 'data': arr, 'cursor':None}
224 tm = [self._gettime(val) for val in range(self.nrow())]
225 if self._vb:
226 self._print_values(retval,stat,tm)
227 return retval
228
229 else:
230 i,j,k = (self.getbeam(),self.getif(),self.getpol())
231 statval = _stats(self,mask,stat,-1)
232 out = ''
233 for l in range(self.nrow()):
234 tm = self._gettime(l)
235 out += 'Time[%s]:\n' % (tm)
236 if self.nbeam() > 1: out += ' Beam[%d] ' % (i)
237 if self.nif() > 1: out += ' IF[%d] ' % (j)
238 if self.npol() > 1: out += ' Pol[%d] ' % (k)
239 out += '= %3.3f\n' % (statval[l])
240 out += "--------------------------------------------------\n"
241
242 if self._vb:
243 print "--------------------------------------------------"
244 print " ",stat
245 print "--------------------------------------------------"
246 print out
247 retval = {'axes': axes, 'data': array(statval), 'cursor':(i,j,k)}
248 return retval
249
250 def stddev(self,mask=None, all=None):
251 """
252 Determine the standard deviation of the current beam/if/pol
253 Takes a 'mask' as an optional parameter to specify which
254 channels should be excluded.
255 Parameters:
256 mask: an optional mask specifying where the standard
257 deviation should be determined.
258 all: optional flag to show all or a cursor selected
259 spectrum of Beam/IF/Pol. Default is all or taken
260 from .asaprc
261
262 Example:
263 scan.set_unit('channel')
264 msk = scan.create_mask([100,200],[500,600])
265 scan.stddev(mask=m)
266 """
267 if all is None: all = rcParams['scantable.allaxes']
268 return self.stats(stat='stddev',mask=mask, all=all);
269
270 def get_tsys(self, all=None):
271 """
272 Return the System temperatures.
273 Parameters:
274 all: optional parameter to get the Tsys values for all
275 Beams/IFs/Pols (default) or just the one selected
276 with scantable.set_cursor()
277 [True or False]
278 Returns:
279 a list of Tsys values.
280 """
281 if all is None: all = rcParams['scantable.allaxes']
282 from numarray import array,zeros,Float
283 axes = ['Beam','IF','Pol','Time']
284
285 if all:
286 n = self.nbeam()*self.nif()*self.npol()*self.nrow()
287 shp = [self.nbeam(),self.nif(),self.npol(),self.nrow()]
288 arr = array(zeros(n),shape=shp,type=Float)
289
290 for i in range(self.nbeam()):
291 self.setbeam(i)
292 for j in range(self.nif()):
293 self.setif(j)
294 for k in range(self.npol()):
295 self.setpol(k)
296 arr[i,j,k,:] = self._gettsys()
297 retval = {'axes': axes, 'data': arr, 'cursor':None}
298 tm = [self._gettime(val) for val in range(self.nrow())]
299 if self._vb:
300 self._print_values(retval,'Tsys',tm)
301 return retval
302
303 else:
304 i,j,k = (self.getbeam(),self.getif(),self.getpol())
305 statval = self._gettsys()
306 out = ''
307 for l in range(self.nrow()):
308 tm = self._gettime(l)
309 out += 'Time[%s]:\n' % (tm)
310 if self.nbeam() > 1: out += ' Beam[%d] ' % (i)
311 if self.nif() > 1: out += ' IF[%d] ' % (j)
312 if self.npol() > 1: out += ' Pol[%d] ' % (k)
313 out += '= %3.3f\n' % (statval[l])
314 out += "--------------------------------------------------\n"
315
316 if self._vb:
317 print "--------------------------------------------------"
318 print " TSys"
319 print "--------------------------------------------------"
320 print out
321 retval = {'axes': axes, 'data': array(statval), 'cursor':(i,j,k)}
322 return retval
323
324 def get_time(self):
325 """
326 Get a list of time stamps for the observations.
327 Return a string for each integration in the scantable.
328 Parameters:
329 none
330 Example:
331 none
332 """
333 out = []
334 for i in range(self.nrow()):
335 out.append(self._gettime(i))
336 return out
337
338 def set_unit(self, unit='channel'):
339 """
340 Set the unit for all following operations on this scantable
341 Parameters:
342 unit: optional unit, default is 'channel'
343 one of '*Hz','km/s','channel', ''
344 """
345
346 if unit in ['','pixel', 'channel']:
347 unit = ''
348 inf = list(self._getcoordinfo())
349 inf[0] = unit
350 self._setcoordinfo(inf)
351 if self._p: self.plot()
352
353 def set_freqframe(self, frame=None):
354 """
355 Set the frame type of the Spectral Axis.
356 Parameters:
357 frame: an optional frame type, default 'LSRK'.
358 Examples:
359 scan.set_freqframe('BARY')
360 """
361 if not frame: frame = rcParams['scantable.freqframe']
362 valid = ['REST','TOPO','LSRD','LSRK','BARY', \
363 'GEO','GALACTO','LGROUP','CMB']
364 if frame in valid:
365 inf = list(self._getcoordinfo())
366 inf[1] = frame
367 self._setcoordinfo(inf)
368 else:
369 print "Please specify a valid freq type. Valid types are:\n",valid
370
371 def get_unit(self):
372 """
373 Get the default unit set in this scantable
374 Parameters:
375 Returns:
376 A unit string
377 """
378 inf = self._getcoordinfo()
379 unit = inf[0]
380 if unit == '': unit = 'channel'
381 return unit
382
383 def get_abcissa(self, rowno=0):
384 """
385 Get the abcissa in the current coordinate setup for the currently
386 selected Beam/IF/Pol
387 Parameters:
388 rowno: an optional row number in the scantable. Default is the
389 first row, i.e. rowno=0
390 Returns:
391 The abcissa values and it's format string.
392 """
393 abc = self._getabcissa(rowno)
394 lbl = self._getabcissalabel(rowno)
395 return abc, lbl
396
397 def create_mask(self, *args, **kwargs):
398 """
399 Compute and return a mask based on [min,max] windows.
400 The specified windows are to be INCLUDED, when the mask is
401 applied.
402 Parameters:
403 [min,max],[min2,max2],...
404 Pairs of start/end points specifying the regions
405 to be masked
406 invert: optional argument. If specified as True,
407 return an inverted mask, i.e. the regions
408 specified are EXCLUDED
409 Example:
410 scan.set_unit('channel')
411
412 a)
413 msk = scan.set_mask([400,500],[800,900])
414 # masks everything outside 400 and 500
415 # and 800 and 900 in the unit 'channel'
416
417 b)
418 msk = scan.set_mask([400,500],[800,900], invert=True)
419 # masks the regions between 400 and 500
420 # and 800 and 900 in the unit 'channel'
421
422 """
423 u = self._getcoordinfo()[0]
424 if self._vb:
425 if u == "": u = "channel"
426 print "The current mask window unit is", u
427 n = self.nchan()
428 data = self._getabcissa()
429 msk = zeros(n)
430 for window in args:
431 if (len(window) != 2 or window[0] > window[1] ):
432 print "A window needs to be defined as [min,max]"
433 return
434 for i in range(n):
435 if data[i] >= window[0] and data[i] < window[1]:
436 msk[i] = 1
437 if kwargs.has_key('invert'):
438 if kwargs.get('invert'):
439 from numarray import logical_not
440 msk = logical_not(msk)
441 return msk
442
443 def set_restfreqs(self, freqs, unit='Hz'):
444 """
445 Set the restfrequency(s) for this scantable.
446 Parameters:
447 freqs: one or more frequencies
448 unit: optional 'unit', default 'Hz'
449 Example:
450 scan.set_restfreqs([1000000000.0])
451 """
452 if type(freqs) is float or int:
453 freqs = (freqs)
454 sdtable._setrestfreqs(self,freqs, unit)
455 return
456 def get_restfreqs(self):
457 """
458 Get the restfrequency(s) stored in this scantable.
459 The return value(s) are always of unit 'Hz'
460 Parameters:
461 none
462 Returns:
463 a list of doubles
464 """
465 return list(self._getrestfreqs())
466
467 def flag_spectrum(self, thebeam, theif, thepol):
468 """
469 This flags a selected spectrum in the scan 'for good'.
470 USE WITH CARE - not reversible.
471 Use masks for non-permanent exclusion of channels.
472 Parameters:
473 thebeam,theif,thepol: all have to be explicitly
474 specified
475 Example:
476 scan.flag_spectrum(0,0,1)
477 flags the spectrum for Beam=0, IF=0, Pol=1
478 """
479 if (thebeam < self.nbeam() and theif < self.nif() and thepol < self.npol()):
480 stable.setbeam(thebeam)
481 stable.setif(theif)
482 stable.setpol(thepol)
483 stable._flag(self)
484 else:
485 print "Please specify a valid (Beam/IF/Pol)"
486 return
487
488 def plot(self, what='spectrum',col='Pol', panel=None):
489 """
490 Plot the spectra contained in the scan. Alternatively you can also
491 Plot Tsys vs Time
492 Parameters:
493 what: a choice of 'spectrum' (default) or 'tsys'
494 col: which out of Beams/IFs/Pols should be colour stacked
495 panel: set up multiple panels, currently not working.
496 """
497 validcol = {'Beam':self.nbeam(),'IF':self.nif(),'Pol':self.npol()}
498
499 validyax = ['spectrum','tsys']
500 from asap.asaplot import ASAPlot
501 if not self._p:
502 self._p = ASAPlot()
503 #print "Plotting not enabled"
504 #return
505 if self._p.is_dead:
506 del self._p
507 self._p = ASAPlot()
508 npan = 1
509 x = None
510 if what == 'tsys':
511 n = self.nrow()
512 if n < 2:
513 print "Only one integration. Can't plot."
514 return
515 self._p.hold()
516 self._p.clear()
517 if panel == 'Time':
518 npan = self.nrow()
519 self._p.set_panels(rows=npan)
520 xlab,ylab,tlab = None,None,None
521 self._vb = False
522 sel = self.get_cursor()
523 for i in range(npan):
524 if npan > 1:
525 self._p.subplot(i)
526 for j in range(validcol[col]):
527 x = None
528 y = None
529 m = None
530 tlab = self._getsourcename(i)
531 import re
532 tlab = re.sub('_S','',tlab)
533 if col == 'Beam':
534 self.setbeam(j)
535 elif col == 'IF':
536 self.setif(j)
537 elif col == 'Pol':
538 self.setpol(j)
539 if what == 'tsys':
540 x = range(self.nrow())
541 xlab = 'Time [pixel]'
542 m = list(ones(len(x)))
543 y = []
544 ylab = r'$T_{sys}$'
545 for k in range(len(x)):
546 y.append(self._gettsys(k))
547 else:
548 x,xlab = self.get_abcissa(i)
549 y = self._getspectrum(i)
550 ylab = r'Flux'
551 m = self._getmask(i)
552 llab = col+' '+str(j)
553 self._p.set_line(label=llab)
554 self._p.plot(x,y,m)
555 self._p.set_axes('xlabel',xlab)
556 self._p.set_axes('ylabel',ylab)
557 self._p.set_axes('title',tlab)
558 self._p.release()
559 self.set_cursor(sel[0],sel[1],sel[2])
560 self._vb = rcParams['verbose']
561 return
562
563 print out
564
565 def _print_values(self, dat, label='', timestamps=[]):
566 d = dat['data']
567 a = dat['axes']
568 shp = d.getshape()
569 out = ''
570 for i in range(shp[3]):
571 out += '%s [%s]:\n' % (a[3],timestamps[i])
572 t = d[:,:,:,i]
573 for j in range(shp[0]):
574 if shp[0] > 1: out += ' %s[%d] ' % (a[0],j)
575 for k in range(shp[1]):
576 if shp[1] > 1: out += ' %s[%d] ' % (a[1],k)
577 for l in range(shp[2]):
578 if shp[2] > 1: out += ' %s[%d] ' % (a[2],l)
579 out += '= %3.3f\n' % (t[j,k,l])
580 out += "--------------------------------------------------\n"
581 print "--------------------------------------------------"
582 print " ", label
583 print "--------------------------------------------------"
584 print out
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