source: trunk/python/scantable.py@ 1369

Last change on this file since 1369 was 1360, checked in by mar637, 18 years ago

enhancement #107; added scantable.shift_refpix

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File size: 65.3 KB
Line 
1from asap._asap import Scantable
2from asap import rcParams
3from asap import print_log
4from asap import asaplog
5from asap import selector
6from asap import linecatalog
7from asap import _n_bools, mask_not, mask_and, mask_or
8
9class scantable(Scantable):
10 """
11 The ASAP container for scans
12 """
13
14 def __init__(self, filename, average=None, unit=None):
15 """
16 Create a scantable from a saved one or make a reference
17 Parameters:
18 filename: the name of an asap table on disk
19 or
20 the name of a rpfits/sdfits/ms file
21 (integrations within scans are auto averaged
22 and the whole file is read)
23 or
24 [advanced] a reference to an existing
25 scantable
26 average: average all integrations withinb a scan on read.
27 The default (True) is taken from .asaprc.
28 unit: brightness unit; must be consistent with K or Jy.
29 Over-rides the default selected by the reader
30 (input rpfits/sdfits/ms) or replaces the value
31 in existing scantables
32 """
33 if average is None:
34 average = rcParams['scantable.autoaverage']
35 varlist = vars()
36 from asap._asap import stmath
37 self._math = stmath()
38 if isinstance(filename, Scantable):
39 Scantable.__init__(self, filename)
40 else:
41 if isinstance(filename, str):
42 import os.path
43 filename = os.path.expandvars(filename)
44 filename = os.path.expanduser(filename)
45 if not os.path.exists(filename):
46 s = "File '%s' not found." % (filename)
47 if rcParams['verbose']:
48 asaplog.push(s)
49 print asaplog.pop().strip()
50 return
51 raise IOError(s)
52 if os.path.isdir(filename) \
53 and not os.path.exists(filename+'/table.f1'):
54 # crude check if asap table
55 if os.path.exists(filename+'/table.info'):
56 ondisk = rcParams['scantable.storage'] == 'disk'
57 Scantable.__init__(self, filename, ondisk)
58 if unit is not None:
59 self.set_fluxunit(unit)
60 self.set_freqframe(rcParams['scantable.freqframe'])
61 else:
62 msg = "The given file '%s'is not a valid " \
63 "asap table." % (filename)
64 if rcParams['verbose']:
65 print msg
66 return
67 else:
68 raise IOError(msg)
69 else:
70 self._fill([filename], unit, average)
71 elif (isinstance(filename, list) or isinstance(filename, tuple)) \
72 and isinstance(filename[-1], str):
73 self._fill(filename, unit, average)
74 self._add_history("scantable", varlist)
75 print_log()
76
77 def save(self, name=None, format=None, overwrite=False):
78 """
79 Store the scantable on disk. This can be an asap (aips++) Table,
80 SDFITS or MS2 format.
81 Parameters:
82 name: the name of the outputfile. For format "ASCII"
83 this is the root file name (data in 'name'.txt
84 and header in 'name'_header.txt)
85 format: an optional file format. Default is ASAP.
86 Allowed are - 'ASAP' (save as ASAP [aips++] Table),
87 'SDFITS' (save as SDFITS file)
88 'ASCII' (saves as ascii text file)
89 'MS2' (saves as an aips++
90 MeasurementSet V2)
91 overwrite: If the file should be overwritten if it exists.
92 The default False is to return with warning
93 without writing the output. USE WITH CARE.
94 Example:
95 scan.save('myscan.asap')
96 scan.save('myscan.sdfits', 'SDFITS')
97 """
98 from os import path
99 if format is None: format = rcParams['scantable.save']
100 suffix = '.'+format.lower()
101 if name is None or name == "":
102 name = 'scantable'+suffix
103 msg = "No filename given. Using default name %s..." % name
104 asaplog.push(msg)
105 name = path.expandvars(name)
106 if path.isfile(name) or path.isdir(name):
107 if not overwrite:
108 msg = "File %s exists." % name
109 if rcParams['verbose']:
110 print msg
111 return
112 else:
113 raise IOError(msg)
114 format2 = format.upper()
115 if format2 == 'ASAP':
116 self._save(name)
117 else:
118 from asap._asap import stwriter as stw
119 writer = stw(format2)
120 writer.write(self, name)
121 print_log()
122 return
123
124 def copy(self):
125 """
126 Return a copy of this scantable.
127 Note:
128 This makes a full (deep) copy. scan2 = scan1 makes a reference.
129 Parameters:
130 none
131 Example:
132 copiedscan = scan.copy()
133 """
134 sd = scantable(Scantable._copy(self))
135 return sd
136
137 def drop_scan(self, scanid=None):
138 """
139 Return a new scantable where the specified scan number(s) has(have)
140 been dropped.
141 Parameters:
142 scanid: a (list of) scan number(s)
143 """
144 from asap import _is_sequence_or_number as _is_valid
145 from asap import _to_list
146 from asap import unique
147 if not _is_valid(scanid):
148 if rcParams['verbose']:
149 print "Please specify a scanno to drop from the scantable"
150 return
151 else:
152 raise RuntimeError("No scan given")
153 try:
154 scanid = _to_list(scanid)
155 allscans = unique([ self.getscan(i) for i in range(self.nrow())])
156 for sid in scanid: allscans.remove(sid)
157 if len(allscans) == 0:
158 raise ValueError("Can't remove all scans")
159 except ValueError:
160 if rcParams['verbose']:
161 print "Couldn't find any match."
162 return
163 else: raise
164 try:
165 bsel = self.get_selection()
166 sel = selector()
167 sel.set_scans(allscans)
168 self.set_selection(bsel+sel)
169 scopy = self._copy()
170 self.set_selection(bsel)
171 return scantable(scopy)
172 except RuntimeError:
173 if rcParams['verbose']:
174 print "Couldn't find any match."
175 else:
176 raise
177
178
179 def get_scan(self, scanid=None):
180 """
181 Return a specific scan (by scanno) or collection of scans (by
182 source name) in a new scantable.
183 Note:
184 See scantable.drop_scan() for the inverse operation.
185 Parameters:
186 scanid: a (list of) scanno or a source name, unix-style
187 patterns are accepted for source name matching, e.g.
188 '*_R' gets all 'ref scans
189 Example:
190 # get all scans containing the source '323p459'
191 newscan = scan.get_scan('323p459')
192 # get all 'off' scans
193 refscans = scan.get_scan('*_R')
194 # get a susbset of scans by scanno (as listed in scan.summary())
195 newscan = scan.get_scan([0, 2, 7, 10])
196 """
197 if scanid is None:
198 if rcParams['verbose']:
199 print "Please specify a scan no or name to " \
200 "retrieve from the scantable"
201 return
202 else:
203 raise RuntimeError("No scan given")
204
205 try:
206 bsel = self.get_selection()
207 sel = selector()
208 if type(scanid) is str:
209 sel.set_name(scanid)
210 self.set_selection(bsel+sel)
211 scopy = self._copy()
212 self.set_selection(bsel)
213 return scantable(scopy)
214 elif type(scanid) is int:
215 sel.set_scans([scanid])
216 self.set_selection(bsel+sel)
217 scopy = self._copy()
218 self.set_selection(bsel)
219 return scantable(scopy)
220 elif type(scanid) is list:
221 sel.set_scans(scanid)
222 self.set_selection(sel)
223 scopy = self._copy()
224 self.set_selection(bsel)
225 return scantable(scopy)
226 else:
227 msg = "Illegal scanid type, use 'int' or 'list' if ints."
228 if rcParams['verbose']:
229 print msg
230 else:
231 raise TypeError(msg)
232 except RuntimeError:
233 if rcParams['verbose']: print "Couldn't find any match."
234 else: raise
235
236 def __str__(self):
237 return Scantable._summary(self, True)
238
239 def summary(self, filename=None):
240 """
241 Print a summary of the contents of this scantable.
242 Parameters:
243 filename: the name of a file to write the putput to
244 Default - no file output
245 verbose: print extra info such as the frequency table
246 The default (False) is taken from .asaprc
247 """
248 info = Scantable._summary(self, True)
249 #if verbose is None: verbose = rcParams['scantable.verbosesummary']
250 if filename is not None:
251 if filename is "":
252 filename = 'scantable_summary.txt'
253 from os.path import expandvars, isdir
254 filename = expandvars(filename)
255 if not isdir(filename):
256 data = open(filename, 'w')
257 data.write(info)
258 data.close()
259 else:
260 msg = "Illegal file name '%s'." % (filename)
261 if rcParams['verbose']:
262 print msg
263 else:
264 raise IOError(msg)
265 if rcParams['verbose']:
266 try:
267 from IPython.genutils import page as pager
268 except ImportError:
269 from pydoc import pager
270 pager(info)
271 else:
272 return info
273
274
275 def get_selection(self):
276 """
277 Get the selection object currently set on this scantable.
278 Parameters:
279 none
280 Example:
281 sel = scan.get_selection()
282 sel.set_ifs(0) # select IF 0
283 scan.set_selection(sel) # apply modified selection
284 """
285 return selector(self._getselection())
286
287 def set_selection(self, selection=selector()):
288 """
289 Select a subset of the data. All following operations on this scantable
290 are only applied to thi selection.
291 Parameters:
292 selection: a selector object (default unset the selection)
293 Examples:
294 sel = selector() # create a selection object
295 self.set_scans([0, 3]) # select SCANNO 0 and 3
296 scan.set_selection(sel) # set the selection
297 scan.summary() # will only print summary of scanno 0 an 3
298 scan.set_selection() # unset the selection
299 """
300 self._setselection(selection)
301
302 def stats(self, stat='stddev', mask=None):
303 """
304 Determine the specified statistic of the current beam/if/pol
305 Takes a 'mask' as an optional parameter to specify which
306 channels should be excluded.
307 Parameters:
308 stat: 'min', 'max', 'sumsq', 'sum', 'mean'
309 'var', 'stddev', 'avdev', 'rms', 'median'
310 mask: an optional mask specifying where the statistic
311 should be determined.
312 Example:
313 scan.set_unit('channel')
314 msk = scan.create_mask([100, 200], [500, 600])
315 scan.stats(stat='mean', mask=m)
316 """
317 if mask == None:
318 mask = []
319 axes = ['Beam', 'IF', 'Pol', 'Time']
320 if not self._check_ifs():
321 raise ValueError("Cannot apply mask as the IFs have different "
322 "number of channels. Please use setselection() "
323 "to select individual IFs")
324
325 statvals = self._math._stats(self, mask, stat)
326 out = ''
327 axes = []
328 for i in range(self.nrow()):
329 axis = []
330 axis.append(self.getscan(i))
331 axis.append(self.getbeam(i))
332 axis.append(self.getif(i))
333 axis.append(self.getpol(i))
334 axis.append(self.getcycle(i))
335 axes.append(axis)
336 tm = self._gettime(i)
337 src = self._getsourcename(i)
338 out += 'Scan[%d] (%s) ' % (axis[0], src)
339 out += 'Time[%s]:\n' % (tm)
340 if self.nbeam(-1) > 1: out += ' Beam[%d] ' % (axis[1])
341 if self.nif(-1) > 1: out += ' IF[%d] ' % (axis[2])
342 if self.npol(-1) > 1: out += ' Pol[%d] ' % (axis[3])
343 out += '= %3.3f\n' % (statvals[i])
344 out += "--------------------------------------------------\n"
345
346 if rcParams['verbose']:
347 print "--------------------------------------------------"
348 print " ", stat
349 print "--------------------------------------------------"
350 print out
351 #else:
352 #retval = { 'axesnames': ['scanno', 'beamno', 'ifno', 'polno', 'cycleno'],
353 # 'axes' : axes,
354 # 'data': statvals}
355 return statvals
356
357 def stddev(self, mask=None):
358 """
359 Determine the standard deviation of the current beam/if/pol
360 Takes a 'mask' as an optional parameter to specify which
361 channels should be excluded.
362 Parameters:
363 mask: an optional mask specifying where the standard
364 deviation should be determined.
365
366 Example:
367 scan.set_unit('channel')
368 msk = scan.create_mask([100, 200], [500, 600])
369 scan.stddev(mask=m)
370 """
371 return self.stats(stat='stddev', mask=mask);
372
373
374 def get_column_names(self):
375 """
376 Return a list of column names, which can be used for selection.
377 """
378 return list(Scantable.get_column_names(self))
379
380 def get_tsys(self):
381 """
382 Return the System temperatures.
383 Returns:
384 a list of Tsys values for the current selection
385 """
386
387 return self._row_callback(self._gettsys, "Tsys")
388
389 def _row_callback(self, callback, label):
390 axes = []
391 axesnames = ['scanno', 'beamno', 'ifno', 'polno', 'cycleno']
392 out = ""
393 outvec = []
394 for i in range(self.nrow()):
395 axis = []
396 axis.append(self.getscan(i))
397 axis.append(self.getbeam(i))
398 axis.append(self.getif(i))
399 axis.append(self.getpol(i))
400 axis.append(self.getcycle(i))
401 axes.append(axis)
402 tm = self._gettime(i)
403 src = self._getsourcename(i)
404 out += 'Scan[%d] (%s) ' % (axis[0], src)
405 out += 'Time[%s]:\n' % (tm)
406 if self.nbeam(-1) > 1: out += ' Beam[%d] ' % (axis[1])
407 if self.nif(-1) > 1: out += ' IF[%d] ' % (axis[2])
408 if self.npol(-1) > 1: out += ' Pol[%d] ' % (axis[3])
409 outvec.append(callback(i))
410 out += '= %3.3f\n' % (outvec[i])
411 out += "--------------------------------------------------\n"
412 if rcParams['verbose']:
413 print "--------------------------------------------------"
414 print " %s" % (label)
415 print "--------------------------------------------------"
416 print out
417 # disabled because the vector seems more useful
418 #retval = {'axesnames': axesnames, 'axes': axes, 'data': outvec}
419 return outvec
420
421 def _get_column(self, callback, row=-1):
422 """
423 """
424 if row == -1:
425 return [callback(i) for i in range(self.nrow())]
426 else:
427 if 0 <= row < self.nrow():
428 return callback(row)
429
430
431 def get_time(self, row=-1, asdatetime=False):
432 """
433 Get a list of time stamps for the observations.
434 Return a datetime object for each integration time stamp in the scantable.
435 Parameters:
436 row: row no of integration. Default -1 return all rows
437 asdatetime: return values as datetime objects rather than strings
438 Example:
439 none
440 """
441 from time import strptime
442 from datetime import datetime
443 if not asdatetime:
444 return self._get_column(self._gettime, row)
445 format = "%Y/%m/%d/%H:%M:%S"
446 if isinstance(times, list):
447 return [datetime(*strptime(i, format)[:6]) for i in times]
448 else:
449 return datetime(*strptime(times, format)[:6])
450
451
452 def get_inttime(self, row=-1):
453 """
454 Get a list of integration times for the observations.
455 Return a time in seconds for each integration in the scantable.
456 Parameters:
457 row: row no of integration. Default -1 return all rows.
458 Example:
459 none
460 """
461 return self._get_column(self._getinttime, row)
462
463
464 def get_sourcename(self, row=-1):
465 """
466 Get a list source names for the observations.
467 Return a string for each integration in the scantable.
468 Parameters:
469 row: row no of integration. Default -1 return all rows.
470 Example:
471 none
472 """
473 return self._get_column(self._getsourcename, row)
474
475 def get_elevation(self, row=-1):
476 """
477 Get a list of elevations for the observations.
478 Return a float for each integration in the scantable.
479 Parameters:
480 row: row no of integration. Default -1 return all rows.
481 Example:
482 none
483 """
484 return self._get_column(self._getelevation, row)
485
486 def get_azimuth(self, row=-1):
487 """
488 Get a list of azimuths for the observations.
489 Return a float for each integration in the scantable.
490 Parameters:
491 row: row no of integration. Default -1 return all rows.
492 Example:
493 none
494 """
495 return self._get_column(self._getazimuth, row)
496
497 def get_parangle(self, row=-1):
498 """
499 Get a list of parallactic angles for the observations.
500 Return a float for each integration in the scantable.
501 Parameters:
502 row: row no of integration. Default -1 return all rows.
503 Example:
504 none
505 """
506 return self._get_column(self._getparangle, row)
507
508 def get_direction(self, row=-1):
509 """
510 Get a list of Positions on the sky (direction) for the observations.
511 Return a float for each integration in the scantable.
512 Parameters:
513 row: row no of integration. Default -1 return all rows
514 Example:
515 none
516 """
517 return self._get_column(self._getdirection, row)
518
519 def set_unit(self, unit='channel'):
520 """
521 Set the unit for all following operations on this scantable
522 Parameters:
523 unit: optional unit, default is 'channel'
524 one of '*Hz', 'km/s', 'channel', ''
525 """
526 varlist = vars()
527 if unit in ['', 'pixel', 'channel']:
528 unit = ''
529 inf = list(self._getcoordinfo())
530 inf[0] = unit
531 self._setcoordinfo(inf)
532 self._add_history("set_unit", varlist)
533
534 def set_instrument(self, instr):
535 """
536 Set the instrument for subsequent processing.
537 Parameters:
538 instr: Select from 'ATPKSMB', 'ATPKSHOH', 'ATMOPRA',
539 'DSS-43' (Tid), 'CEDUNA', and 'HOBART'
540 """
541 self._setInstrument(instr)
542 self._add_history("set_instument", vars())
543 print_log()
544
545 def set_feedtype(self, feedtype):
546 """
547 Overwrite the feed type, which might not be set correctly.
548 Parameters:
549 feedtype: 'linear' or 'circular'
550 """
551 self._setfeedtype(feedtype)
552 self._add_history("set_feedtype", vars())
553 print_log()
554
555 def set_doppler(self, doppler='RADIO'):
556 """
557 Set the doppler for all following operations on this scantable.
558 Parameters:
559 doppler: One of 'RADIO', 'OPTICAL', 'Z', 'BETA', 'GAMMA'
560 """
561 varlist = vars()
562 inf = list(self._getcoordinfo())
563 inf[2] = doppler
564 self._setcoordinfo(inf)
565 self._add_history("set_doppler", vars())
566 print_log()
567
568 def set_freqframe(self, frame=None):
569 """
570 Set the frame type of the Spectral Axis.
571 Parameters:
572 frame: an optional frame type, default 'LSRK'. Valid frames are:
573 'REST', 'TOPO', 'LSRD', 'LSRK', 'BARY',
574 'GEO', 'GALACTO', 'LGROUP', 'CMB'
575 Examples:
576 scan.set_freqframe('BARY')
577 """
578 if frame is None: frame = rcParams['scantable.freqframe']
579 varlist = vars()
580 valid = ['REST', 'TOPO', 'LSRD', 'LSRK', 'BARY', \
581 'GEO', 'GALACTO', 'LGROUP', 'CMB']
582
583 if frame in valid:
584 inf = list(self._getcoordinfo())
585 inf[1] = frame
586 self._setcoordinfo(inf)
587 self._add_history("set_freqframe", varlist)
588 else:
589 msg = "Please specify a valid freq type. Valid types are:\n", valid
590 if rcParams['verbose']:
591 print msg
592 else:
593 raise TypeError(msg)
594 print_log()
595
596 def set_dirframe(self, frame=""):
597 """
598 Set the frame type of the Direction on the sky.
599 Parameters:
600 frame: an optional frame type, default ''. Valid frames are:
601 'J2000', 'B1950', 'GALACTIC'
602 Examples:
603 scan.set_dirframe('GALACTIC')
604 """
605 varlist = vars()
606 try:
607 Scantable.set_dirframe(self, frame)
608 except RuntimeError, msg:
609 if rcParams['verbose']:
610 print msg
611 else:
612 raise
613 self._add_history("set_dirframe", varlist)
614
615 def get_unit(self):
616 """
617 Get the default unit set in this scantable
618 Returns:
619 A unit string
620 """
621 inf = self._getcoordinfo()
622 unit = inf[0]
623 if unit == '': unit = 'channel'
624 return unit
625
626 def get_abcissa(self, rowno=0):
627 """
628 Get the abcissa in the current coordinate setup for the currently
629 selected Beam/IF/Pol
630 Parameters:
631 rowno: an optional row number in the scantable. Default is the
632 first row, i.e. rowno=0
633 Returns:
634 The abcissa values and the format string (as a dictionary)
635 """
636 abc = self._getabcissa(rowno)
637 lbl = self._getabcissalabel(rowno)
638 print_log()
639 return abc, lbl
640
641 def flag(self, mask=None):
642 """
643 Flag the selected data using an optional channel mask.
644 Parameters:
645 mask: an optional channel mask, created with create_mask. Default
646 (no mask) is all channels.
647 """
648 varlist = vars()
649 if mask is None:
650 mask = []
651 try:
652 self._flag(mask)
653 except RuntimeError, msg:
654 if rcParams['verbose']:
655 print msg
656 return
657 else: raise
658 self._add_history("flag", varlist)
659
660 def lag_flag(self, frequency, width=0.0, unit="GHz", insitu=None):
661 """
662 Flag the data in 'lag' space by providing a frequency to remove.
663 Flagged data in the scantable gets set to 0.0 before the fft.
664 No taper is applied.
665 Parameters:
666 frequency: the frequency (really a period within the bandwidth)
667 to remove
668 width: the width of the frequency to remove, to remove a
669 range of frequencies aroung the centre.
670 unit: the frequency unit (default "GHz")
671 Notes:
672 It is recommended to flag edges of the band or strong
673 signals beforehand.
674 """
675 if insitu is None: insitu = rcParams['insitu']
676 self._math._setinsitu(insitu)
677 varlist = vars()
678 base = { "GHz": 100000000., "MHz": 1000000., "kHz": 1000., "Hz": 1. }
679 if not base.has_key(unit):
680 raise ValueError("%s is not a valid unit." % unit)
681 try:
682 s = scantable(self._math._lag_flag(self, frequency*base[unit],
683 width*base[unit]))
684 except RuntimeError, msg:
685 if rcParams['verbose']:
686 print msg
687 return
688 else: raise
689 s._add_history("lag_flag", varlist)
690 print_log()
691 if insitu:
692 self._assign(s)
693 else:
694 return s
695
696
697 def create_mask(self, *args, **kwargs):
698 """
699 Compute and return a mask based on [min, max] windows.
700 The specified windows are to be INCLUDED, when the mask is
701 applied.
702 Parameters:
703 [min, max], [min2, max2], ...
704 Pairs of start/end points (inclusive)specifying the regions
705 to be masked
706 invert: optional argument. If specified as True,
707 return an inverted mask, i.e. the regions
708 specified are EXCLUDED
709 row: create the mask using the specified row for
710 unit conversions, default is row=0
711 only necessary if frequency varies over rows.
712 Example:
713 scan.set_unit('channel')
714 a)
715 msk = scan.create_mask([400, 500], [800, 900])
716 # masks everything outside 400 and 500
717 # and 800 and 900 in the unit 'channel'
718
719 b)
720 msk = scan.create_mask([400, 500], [800, 900], invert=True)
721 # masks the regions between 400 and 500
722 # and 800 and 900 in the unit 'channel'
723 c)
724 mask only channel 400
725 msk = scan.create_mask([400, 400])
726 """
727 row = 0
728 if kwargs.has_key("row"):
729 row = kwargs.get("row")
730 data = self._getabcissa(row)
731 u = self._getcoordinfo()[0]
732 if rcParams['verbose']:
733 if u == "": u = "channel"
734 msg = "The current mask window unit is %s" % u
735 i = self._check_ifs()
736 if not i:
737 msg += "\nThis mask is only valid for IF=%d" % (self.getif(i))
738 asaplog.push(msg)
739 n = self.nchan()
740 msk = _n_bools(n, False)
741 # test if args is a 'list' or a 'normal *args - UGLY!!!
742
743 ws = (isinstance(args[-1][-1], int) or isinstance(args[-1][-1], float)) \
744 and args or args[0]
745 for window in ws:
746 if (len(window) != 2 or window[0] > window[1] ):
747 raise TypeError("A window needs to be defined as [min, max]")
748 for i in range(n):
749 if data[i] >= window[0] and data[i] <= window[1]:
750 msk[i] = True
751 if kwargs.has_key('invert'):
752 if kwargs.get('invert'):
753 msk = mask_not(msk)
754 print_log()
755 return msk
756
757 def get_restfreqs(self):
758 """
759 Get the restfrequency(s) stored in this scantable.
760 The return value(s) are always of unit 'Hz'
761 Parameters:
762 none
763 Returns:
764 a list of doubles
765 """
766 return list(self._getrestfreqs())
767
768
769 def set_restfreqs(self, freqs=None, unit='Hz'):
770 """
771 Set or replace the restfrequency specified and
772 If the 'freqs' argument holds a scalar,
773 then that rest frequency will be applied to all the selected
774 data. If the 'freqs' argument holds
775 a vector, then it MUST be of equal or smaller length than
776 the number of IFs (and the available restfrequencies will be
777 replaced by this vector). In this case, *all* data have
778 the restfrequency set per IF according
779 to the corresponding value you give in the 'freqs' vector.
780 E.g. 'freqs=[1e9, 2e9]' would mean IF 0 gets restfreq 1e9 and
781 IF 1 gets restfreq 2e9.
782 You can also specify the frequencies via a linecatalog/
783
784 Parameters:
785 freqs: list of rest frequency values or string idenitfiers
786 unit: unit for rest frequency (default 'Hz')
787
788 Example:
789 # set the given restfrequency for the whole table
790 scan.set_restfreqs(freqs=1.4e9)
791 # If thee number of IFs in the data is >= 2 IF0 gets the first
792 # value IF1 the second...
793 scan.set_restfreqs(freqs=[1.4e9, 1.67e9])
794 #set the given restfrequency for the whole table (by name)
795 scan.set_restfreqs(freqs="OH1667")
796
797 Note:
798 To do more sophisticate Restfrequency setting, e.g. on a
799 source and IF basis, use scantable.set_selection() before using
800 this function.
801 # provide your scantable is call scan
802 selection = selector()
803 selection.set_name("ORION*")
804 selection.set_ifs([1])
805 scan.set_selection(selection)
806 scan.set_restfreqs(freqs=86.6e9)
807
808 """
809 varlist = vars()
810 from asap import linecatalog
811 # simple value
812 if isinstance(freqs, int) or isinstance(freqs, float):
813 self._setrestfreqs(freqs, "",unit)
814 # list of values
815 elif isinstance(freqs, list) or isinstance(freqs, tuple):
816 # list values are scalars
817 if isinstance(freqs[-1], int) or isinstance(freqs[-1], float):
818 sel = selector()
819 savesel = self._getselection()
820 iflist = self.getifnos()
821 for i in xrange(len(freqs)):
822 sel.set_ifs(iflist[i])
823 self._setselection(sel)
824 self._setrestfreqs(freqs[i], "",unit)
825 self._setselection(savesel)
826 # list values are tuples, (value, name)
827 elif isinstance(freqs[-1], dict):
828 sel = selector()
829 savesel = self._getselection()
830 iflist = self.getifnos()
831 for i in xrange(len(freqs)):
832 sel.set_ifs(iflist[i])
833 self._setselection(sel)
834 self._setrestfreqs(freqs[i]["value"],
835 freqs[i]["name"], "MHz")
836 self._setselection(savesel)
837 # freqs are to be taken from a linecatalog
838 elif isinstance(freqs, linecatalog):
839 sel = selector()
840 savesel = self._getselection()
841 iflist = self.getifnos()
842 for i in xrange(freqs.nrow()):
843 sel.set_ifs(iflist[i])
844 self._setselection(sel)
845 self._setrestfreqs(freqs.get_frequency(i),
846 freqs.get_name(i), "MHz")
847 # ensure that we are not iterating past nIF
848 if i == self.nif()-1: break
849 self._setselection(savesel)
850 else:
851 return
852 self._add_history("set_restfreqs", varlist)
853
854 def shift_refpix(self, delta):
855 """
856 Shift the reference pixel of the Spectra Coordinate by an
857 integer amount.
858 Parameters:
859 delta: the amount to shift by
860 Note:
861 Be careful using this with broadband data.
862 """
863 Scantable.shift(self, delta)
864
865 def history(self, filename=None):
866 """
867 Print the history. Optionally to a file.
868 Parameters:
869 filename: The name of the file to save the history to.
870 """
871 hist = list(self._gethistory())
872 out = "-"*80
873 for h in hist:
874 if h.startswith("---"):
875 out += "\n"+h
876 else:
877 items = h.split("##")
878 date = items[0]
879 func = items[1]
880 items = items[2:]
881 out += "\n"+date+"\n"
882 out += "Function: %s\n Parameters:" % (func)
883 for i in items:
884 s = i.split("=")
885 out += "\n %s = %s" % (s[0], s[1])
886 out += "\n"+"-"*80
887 if filename is not None:
888 if filename is "":
889 filename = 'scantable_history.txt'
890 import os
891 filename = os.path.expandvars(os.path.expanduser(filename))
892 if not os.path.isdir(filename):
893 data = open(filename, 'w')
894 data.write(out)
895 data.close()
896 else:
897 msg = "Illegal file name '%s'." % (filename)
898 if rcParams['verbose']:
899 print msg
900 else:
901 raise IOError(msg)
902 if rcParams['verbose']:
903 try:
904 from IPython.genutils import page as pager
905 except ImportError:
906 from pydoc import pager
907 pager(out)
908 else:
909 return out
910 return
911 #
912 # Maths business
913 #
914
915 def average_time(self, mask=None, scanav=False, weight='tint', align=False):
916 """
917 Return the (time) weighted average of a scan.
918 Note:
919 in channels only - align if necessary
920 Parameters:
921 mask: an optional mask (only used for 'var' and 'tsys'
922 weighting)
923 scanav: True averages each scan separately
924 False (default) averages all scans together,
925 weight: Weighting scheme.
926 'none' (mean no weight)
927 'var' (1/var(spec) weighted)
928 'tsys' (1/Tsys**2 weighted)
929 'tint' (integration time weighted)
930 'tintsys' (Tint/Tsys**2)
931 'median' ( median averaging)
932 The default is 'tint'
933 align: align the spectra in velocity before averaging. It takes
934 the time of the first spectrum as reference time.
935 Example:
936 # time average the scantable without using a mask
937 newscan = scan.average_time()
938 """
939 varlist = vars()
940 if weight is None: weight = 'TINT'
941 if mask is None: mask = ()
942 if scanav: scanav = "SCAN"
943 else: scanav = "NONE"
944 scan = (self, )
945 try:
946 if align:
947 scan = (self.freq_align(insitu=False), )
948 s = None
949 if weight.upper() == 'MEDIAN':
950 s = scantable(self._math._averagechannel(scan[0], 'MEDIAN',
951 scanav))
952 else:
953 s = scantable(self._math._average(scan, mask, weight.upper(),
954 scanav))
955 except RuntimeError, msg:
956 if rcParams['verbose']:
957 print msg
958 return
959 else: raise
960 s._add_history("average_time", varlist)
961 print_log()
962 return s
963
964 def convert_flux(self, jyperk=None, eta=None, d=None, insitu=None):
965 """
966 Return a scan where all spectra are converted to either
967 Jansky or Kelvin depending upon the flux units of the scan table.
968 By default the function tries to look the values up internally.
969 If it can't find them (or if you want to over-ride), you must
970 specify EITHER jyperk OR eta (and D which it will try to look up
971 also if you don't set it). jyperk takes precedence if you set both.
972 Parameters:
973 jyperk: the Jy / K conversion factor
974 eta: the aperture efficiency
975 d: the geomtric diameter (metres)
976 insitu: if False a new scantable is returned.
977 Otherwise, the scaling is done in-situ
978 The default is taken from .asaprc (False)
979 """
980 if insitu is None: insitu = rcParams['insitu']
981 self._math._setinsitu(insitu)
982 varlist = vars()
983 if jyperk is None: jyperk = -1.0
984 if d is None: d = -1.0
985 if eta is None: eta = -1.0
986 s = scantable(self._math._convertflux(self, d, eta, jyperk))
987 s._add_history("convert_flux", varlist)
988 print_log()
989 if insitu: self._assign(s)
990 else: return s
991
992 def gain_el(self, poly=None, filename="", method="linear", insitu=None):
993 """
994 Return a scan after applying a gain-elevation correction.
995 The correction can be made via either a polynomial or a
996 table-based interpolation (and extrapolation if necessary).
997 You specify polynomial coefficients, an ascii table or neither.
998 If you specify neither, then a polynomial correction will be made
999 with built in coefficients known for certain telescopes (an error
1000 will occur if the instrument is not known).
1001 The data and Tsys are *divided* by the scaling factors.
1002 Parameters:
1003 poly: Polynomial coefficients (default None) to compute a
1004 gain-elevation correction as a function of
1005 elevation (in degrees).
1006 filename: The name of an ascii file holding correction factors.
1007 The first row of the ascii file must give the column
1008 names and these MUST include columns
1009 "ELEVATION" (degrees) and "FACTOR" (multiply data
1010 by this) somewhere.
1011 The second row must give the data type of the
1012 column. Use 'R' for Real and 'I' for Integer.
1013 An example file would be
1014 (actual factors are arbitrary) :
1015
1016 TIME ELEVATION FACTOR
1017 R R R
1018 0.1 0 0.8
1019 0.2 20 0.85
1020 0.3 40 0.9
1021 0.4 60 0.85
1022 0.5 80 0.8
1023 0.6 90 0.75
1024 method: Interpolation method when correcting from a table.
1025 Values are "nearest", "linear" (default), "cubic"
1026 and "spline"
1027 insitu: if False a new scantable is returned.
1028 Otherwise, the scaling is done in-situ
1029 The default is taken from .asaprc (False)
1030 """
1031
1032 if insitu is None: insitu = rcParams['insitu']
1033 self._math._setinsitu(insitu)
1034 varlist = vars()
1035 if poly is None:
1036 poly = ()
1037 from os.path import expandvars
1038 filename = expandvars(filename)
1039 s = scantable(self._math._gainel(self, poly, filename, method))
1040 s._add_history("gain_el", varlist)
1041 print_log()
1042 if insitu: self._assign(s)
1043 else: return s
1044
1045 def freq_align(self, reftime=None, method='cubic', insitu=None):
1046 """
1047 Return a scan where all rows have been aligned in frequency/velocity.
1048 The alignment frequency frame (e.g. LSRK) is that set by function
1049 set_freqframe.
1050 Parameters:
1051 reftime: reference time to align at. By default, the time of
1052 the first row of data is used.
1053 method: Interpolation method for regridding the spectra.
1054 Choose from "nearest", "linear", "cubic" (default)
1055 and "spline"
1056 insitu: if False a new scantable is returned.
1057 Otherwise, the scaling is done in-situ
1058 The default is taken from .asaprc (False)
1059 """
1060 if insitu is None: insitu = rcParams["insitu"]
1061 self._math._setinsitu(insitu)
1062 varlist = vars()
1063 if reftime is None: reftime = ""
1064 s = scantable(self._math._freq_align(self, reftime, method))
1065 s._add_history("freq_align", varlist)
1066 print_log()
1067 if insitu: self._assign(s)
1068 else: return s
1069
1070 def opacity(self, tau, insitu=None):
1071 """
1072 Apply an opacity correction. The data
1073 and Tsys are multiplied by the correction factor.
1074 Parameters:
1075 tau: Opacity from which the correction factor is
1076 exp(tau*ZD)
1077 where ZD is the zenith-distance
1078 insitu: if False a new scantable is returned.
1079 Otherwise, the scaling is done in-situ
1080 The default is taken from .asaprc (False)
1081 """
1082 if insitu is None: insitu = rcParams['insitu']
1083 self._math._setinsitu(insitu)
1084 varlist = vars()
1085 s = scantable(self._math._opacity(self, tau))
1086 s._add_history("opacity", varlist)
1087 print_log()
1088 if insitu: self._assign(s)
1089 else: return s
1090
1091 def bin(self, width=5, insitu=None):
1092 """
1093 Return a scan where all spectra have been binned up.
1094 Parameters:
1095 width: The bin width (default=5) in pixels
1096 insitu: if False a new scantable is returned.
1097 Otherwise, the scaling is done in-situ
1098 The default is taken from .asaprc (False)
1099 """
1100 if insitu is None: insitu = rcParams['insitu']
1101 self._math._setinsitu(insitu)
1102 varlist = vars()
1103 s = scantable(self._math._bin(self, width))
1104 s._add_history("bin", varlist)
1105 print_log()
1106 if insitu: self._assign(s)
1107 else: return s
1108
1109
1110 def resample(self, width=5, method='cubic', insitu=None):
1111 """
1112 Return a scan where all spectra have been binned up.
1113
1114 Parameters:
1115 width: The bin width (default=5) in pixels
1116 method: Interpolation method when correcting from a table.
1117 Values are "nearest", "linear", "cubic" (default)
1118 and "spline"
1119 insitu: if False a new scantable is returned.
1120 Otherwise, the scaling is done in-situ
1121 The default is taken from .asaprc (False)
1122 """
1123 if insitu is None: insitu = rcParams['insitu']
1124 self._math._setinsitu(insitu)
1125 varlist = vars()
1126 s = scantable(self._math._resample(self, method, width))
1127 s._add_history("resample", varlist)
1128 print_log()
1129 if insitu: self._assign(s)
1130 else: return s
1131
1132
1133 def average_pol(self, mask=None, weight='none'):
1134 """
1135 Average the Polarisations together.
1136 Parameters:
1137 mask: An optional mask defining the region, where the
1138 averaging will be applied. The output will have all
1139 specified points masked.
1140 weight: Weighting scheme. 'none' (default), 'var' (1/var(spec)
1141 weighted), or 'tsys' (1/Tsys**2 weighted)
1142 """
1143 varlist = vars()
1144 if mask is None:
1145 mask = ()
1146 s = scantable(self._math._averagepol(self, mask, weight.upper()))
1147 s._add_history("average_pol", varlist)
1148 print_log()
1149 return s
1150
1151 def average_beam(self, mask=None, weight='none'):
1152 """
1153 Average the Beams together.
1154 Parameters:
1155 mask: An optional mask defining the region, where the
1156 averaging will be applied. The output will have all
1157 specified points masked.
1158 weight: Weighting scheme. 'none' (default), 'var' (1/var(spec)
1159 weighted), or 'tsys' (1/Tsys**2 weighted)
1160 """
1161 varlist = vars()
1162 if mask is None:
1163 mask = ()
1164 s = scantable(self._math._averagebeams(self, mask, weight.upper()))
1165 s._add_history("average_beam", varlist)
1166 print_log()
1167 return s
1168
1169 def convert_pol(self, poltype=None):
1170 """
1171 Convert the data to a different polarisation type.
1172 Parameters:
1173 poltype: The new polarisation type. Valid types are:
1174 "linear", "stokes" and "circular"
1175 """
1176 varlist = vars()
1177 try:
1178 s = scantable(self._math._convertpol(self, poltype))
1179 except RuntimeError, msg:
1180 if rcParams['verbose']:
1181 print msg
1182 return
1183 else:
1184 raise
1185 s._add_history("convert_pol", varlist)
1186 print_log()
1187 return s
1188
1189 def smooth(self, kernel="hanning", width=5.0, insitu=None):
1190 """
1191 Smooth the spectrum by the specified kernel (conserving flux).
1192 Parameters:
1193 kernel: The type of smoothing kernel. Select from
1194 'hanning' (default), 'gaussian' and 'boxcar'.
1195 The first three characters are sufficient.
1196 width: The width of the kernel in pixels. For hanning this is
1197 ignored otherwise it defauls to 5 pixels.
1198 For 'gaussian' it is the Full Width Half
1199 Maximum. For 'boxcar' it is the full width.
1200 insitu: if False a new scantable is returned.
1201 Otherwise, the scaling is done in-situ
1202 The default is taken from .asaprc (False)
1203 Example:
1204 none
1205 """
1206 if insitu is None: insitu = rcParams['insitu']
1207 self._math._setinsitu(insitu)
1208 varlist = vars()
1209 s = scantable(self._math._smooth(self, kernel.lower(), width))
1210 s._add_history("smooth", varlist)
1211 print_log()
1212 if insitu: self._assign(s)
1213 else: return s
1214
1215
1216 def poly_baseline(self, mask=None, order=0, plot=False, insitu=None):
1217 """
1218 Return a scan which has been baselined (all rows) by a polynomial.
1219 Parameters:
1220 mask: an optional mask
1221 order: the order of the polynomial (default is 0)
1222 plot: plot the fit and the residual. In this each
1223 indivual fit has to be approved, by typing 'y'
1224 or 'n'
1225 insitu: if False a new scantable is returned.
1226 Otherwise, the scaling is done in-situ
1227 The default is taken from .asaprc (False)
1228 Example:
1229 # return a scan baselined by a third order polynomial,
1230 # not using a mask
1231 bscan = scan.poly_baseline(order=3)
1232 """
1233 if insitu is None: insitu = rcParams['insitu']
1234 varlist = vars()
1235 if mask is None:
1236 mask = [True for i in xrange(self.nchan(-1))]
1237 from asap.asapfitter import fitter
1238 try:
1239 f = fitter()
1240 f.set_scan(self, mask)
1241 f.set_function(poly=order)
1242 s = f.auto_fit(insitu, plot=plot)
1243 s._add_history("poly_baseline", varlist)
1244 print_log()
1245 if insitu: self._assign(s)
1246 else: return s
1247 except RuntimeError:
1248 msg = "The fit failed, possibly because it didn't converge."
1249 if rcParams['verbose']:
1250 print msg
1251 return
1252 else:
1253 raise RuntimeError(msg)
1254
1255
1256 def auto_poly_baseline(self, mask=[], edge=(0, 0), order=0,
1257 threshold=3, chan_avg_limit=1, plot=False,
1258 insitu=None):
1259 """
1260 Return a scan which has been baselined (all rows) by a polynomial.
1261 Spectral lines are detected first using linefinder and masked out
1262 to avoid them affecting the baseline solution.
1263
1264 Parameters:
1265 mask: an optional mask retreived from scantable
1266 edge: an optional number of channel to drop at
1267 the edge of spectrum. If only one value is
1268 specified, the same number will be dropped from
1269 both sides of the spectrum. Default is to keep
1270 all channels. Nested tuples represent individual
1271 edge selection for different IFs (a number of spectral
1272 channels can be different)
1273 order: the order of the polynomial (default is 0)
1274 threshold: the threshold used by line finder. It is better to
1275 keep it large as only strong lines affect the
1276 baseline solution.
1277 chan_avg_limit:
1278 a maximum number of consequtive spectral channels to
1279 average during the search of weak and broad lines.
1280 The default is no averaging (and no search for weak
1281 lines). If such lines can affect the fitted baseline
1282 (e.g. a high order polynomial is fitted), increase this
1283 parameter (usually values up to 8 are reasonable). Most
1284 users of this method should find the default value
1285 sufficient.
1286 plot: plot the fit and the residual. In this each
1287 indivual fit has to be approved, by typing 'y'
1288 or 'n'
1289 insitu: if False a new scantable is returned.
1290 Otherwise, the scaling is done in-situ
1291 The default is taken from .asaprc (False)
1292
1293 Example:
1294 scan2=scan.auto_poly_baseline(order=7)
1295 """
1296 if insitu is None: insitu = rcParams['insitu']
1297 varlist = vars()
1298 from asap.asapfitter import fitter
1299 from asap.asaplinefind import linefinder
1300 from asap import _is_sequence_or_number as _is_valid
1301
1302 # check whether edge is set up for each IF individually
1303 individualedge = False;
1304 if len(edge) > 1:
1305 if isinstance(edge[0], list) or isinstance(edge[0], tuple):
1306 individualedge = True;
1307
1308 if not _is_valid(edge, int) and not individualedge:
1309 raise ValueError, "Parameter 'edge' has to be an integer or a \
1310 pair of integers specified as a tuple. Nested tuples are allowed \
1311 to make individual selection for different IFs."
1312
1313 curedge = (0, 0)
1314 if individualedge:
1315 for edgepar in edge:
1316 if not _is_valid(edgepar, int):
1317 raise ValueError, "Each element of the 'edge' tuple has \
1318 to be a pair of integers or an integer."
1319 else:
1320 curedge = edge;
1321
1322 # setup fitter
1323 f = fitter()
1324 f.set_function(poly=order)
1325
1326 # setup line finder
1327 fl = linefinder()
1328 fl.set_options(threshold=threshold,avg_limit=chan_avg_limit)
1329
1330 if not insitu:
1331 workscan = self.copy()
1332 else:
1333 workscan = self
1334
1335 fl.set_scan(workscan)
1336
1337 rows = range(workscan.nrow())
1338 asaplog.push("Processing:")
1339 for r in rows:
1340 msg = " Scan[%d] Beam[%d] IF[%d] Pol[%d] Cycle[%d]" % \
1341 (workscan.getscan(r), workscan.getbeam(r), workscan.getif(r), \
1342 workscan.getpol(r), workscan.getcycle(r))
1343 asaplog.push(msg, False)
1344
1345 # figure out edge parameter
1346 if individualedge:
1347 if len(edge) >= workscan.getif(r):
1348 raise RuntimeError, "Number of edge elements appear to " \
1349 "be less than the number of IFs"
1350 curedge = edge[workscan.getif(r)]
1351
1352 # setup line finder
1353 fl.find_lines(r, mask, curedge)
1354 f.set_scan(workscan, fl.get_mask())
1355 f.x = workscan._getabcissa(r)
1356 f.y = workscan._getspectrum(r)
1357 f.data = None
1358 f.fit()
1359 x = f.get_parameters()
1360 if plot:
1361 f.plot(residual=True)
1362 x = raw_input("Accept fit ( [y]/n ): ")
1363 if x.upper() == 'N':
1364 continue
1365 workscan._setspectrum(f.fitter.getresidual(), r)
1366 if plot:
1367 f._p.unmap()
1368 f._p = None
1369 workscan._add_history("auto_poly_baseline", varlist)
1370 if insitu:
1371 self._assign(workscan)
1372 else:
1373 return workscan
1374
1375 def rotate_linpolphase(self, angle):
1376 """
1377 Rotate the phase of the complex polarization O=Q+iU correlation.
1378 This is always done in situ in the raw data. So if you call this
1379 function more than once then each call rotates the phase further.
1380 Parameters:
1381 angle: The angle (degrees) to rotate (add) by.
1382 Examples:
1383 scan.rotate_linpolphase(2.3)
1384 """
1385 varlist = vars()
1386 self._math._rotate_linpolphase(self, angle)
1387 self._add_history("rotate_linpolphase", varlist)
1388 print_log()
1389 return
1390
1391
1392 def rotate_xyphase(self, angle):
1393 """
1394 Rotate the phase of the XY correlation. This is always done in situ
1395 in the data. So if you call this function more than once
1396 then each call rotates the phase further.
1397 Parameters:
1398 angle: The angle (degrees) to rotate (add) by.
1399 Examples:
1400 scan.rotate_xyphase(2.3)
1401 """
1402 varlist = vars()
1403 self._math._rotate_xyphase(self, angle)
1404 self._add_history("rotate_xyphase", varlist)
1405 print_log()
1406 return
1407
1408 def swap_linears(self):
1409 """
1410 Swap the linear polarisations XX and YY, or better the first two
1411 polarisations as this also works for ciculars.
1412 """
1413 varlist = vars()
1414 self._math._swap_linears(self)
1415 self._add_history("swap_linears", varlist)
1416 print_log()
1417 return
1418
1419 def invert_phase(self):
1420 """
1421 Invert the phase of the complex polarisation
1422 """
1423 varlist = vars()
1424 self._math._invert_phase(self)
1425 self._add_history("invert_phase", varlist)
1426 print_log()
1427 return
1428
1429 def add(self, offset, insitu=None):
1430 """
1431 Return a scan where all spectra have the offset added
1432 Parameters:
1433 offset: the offset
1434 insitu: if False a new scantable is returned.
1435 Otherwise, the scaling is done in-situ
1436 The default is taken from .asaprc (False)
1437 """
1438 if insitu is None: insitu = rcParams['insitu']
1439 self._math._setinsitu(insitu)
1440 varlist = vars()
1441 s = scantable(self._math._unaryop(self, offset, "ADD", False))
1442 s._add_history("add", varlist)
1443 print_log()
1444 if insitu:
1445 self._assign(s)
1446 else:
1447 return s
1448
1449 def scale(self, factor, tsys=True, insitu=None):
1450 """
1451 Return a scan where all spectra are scaled by the give 'factor'
1452 Parameters:
1453 factor: the scaling factor
1454 insitu: if False a new scantable is returned.
1455 Otherwise, the scaling is done in-situ
1456 The default is taken from .asaprc (False)
1457 tsys: if True (default) then apply the operation to Tsys
1458 as well as the data
1459 """
1460 if insitu is None: insitu = rcParams['insitu']
1461 self._math._setinsitu(insitu)
1462 varlist = vars()
1463 s = scantable(self._math._unaryop(self, factor, "MUL", tsys))
1464 s._add_history("scale", varlist)
1465 print_log()
1466 if insitu:
1467 self._assign(s)
1468 else:
1469 return s
1470
1471 def auto_quotient(self, preserve=True, mode='paired'):
1472 """
1473 This function allows to build quotients automatically.
1474 It assumes the observation to have the same numer of
1475 "ons" and "offs"
1476 Parameters:
1477 preserve: you can preserve (default) the continuum or
1478 remove it. The equations used are
1479 preserve: Output = Toff * (on/off) - Toff
1480 remove: Output = Toff * (on/off) - Ton
1481 mode: the on/off detection mode
1482 'paired' (default)
1483 identifies 'off' scans by the
1484 trailing '_R' (Mopra/Parkes) or
1485 '_e'/'_w' (Tid) and matches
1486 on/off pairs from the observing pattern
1487 'time'
1488 finds the closest off in time
1489
1490 """
1491 modes = ["time", "paired"]
1492 if not mode in modes:
1493 msg = "please provide valid mode. Valid modes are %s" % (modes)
1494 raise ValueError(msg)
1495 varlist = vars()
1496 s = None
1497 if mode.lower() == "paired":
1498 basesel = self.get_selection()
1499 sel = selector()+basesel
1500 sel.set_query("SRCTYPE==1")
1501 self.set_selection(sel)
1502 offs = self.copy()
1503 sel.set_query("SRCTYPE==0")
1504 self.set_selection(sel)
1505 ons = self.copy()
1506 s = scantable(self._math._quotient(ons, offs, preserve))
1507 self.set_selection(basesel)
1508 elif mode.lower() == "time":
1509 s = scantable(self._math._auto_quotient(self, mode, preserve))
1510 s._add_history("auto_quotient", varlist)
1511 print_log()
1512 return s
1513
1514 def mx_quotient(self, mask = None, weight='median', preserve=True):
1515 """
1516 Form a quotient using "off" beams when observing in "MX" mode.
1517 Parameters:
1518 mask: an optional mask to be used when weight == 'stddev'
1519 weight: How to average the off beams. Default is 'median'.
1520 preserve: you can preserve (default) the continuum or
1521 remove it. The equations used are
1522 preserve: Output = Toff * (on/off) - Toff
1523 remove: Output = Toff * (on/off) - Ton
1524 """
1525 if mask is None: mask = ()
1526 varlist = vars()
1527 on = scantable(self._math._mx_extract(self, 'on'))
1528 preoff = scantable(self._math._mx_extract(self, 'off'))
1529 off = preoff.average_time(mask=mask, weight=weight, scanav=False)
1530 from asapmath import quotient
1531 q = quotient(on, off, preserve)
1532 q._add_history("mx_quotient", varlist)
1533 print_log()
1534 return q
1535
1536 def freq_switch(self, insitu=None):
1537 """
1538 Apply frequency switching to the data.
1539 Parameters:
1540 insitu: if False a new scantable is returned.
1541 Otherwise, the swictching is done in-situ
1542 The default is taken from .asaprc (False)
1543 Example:
1544 none
1545 """
1546 if insitu is None: insitu = rcParams['insitu']
1547 self._math._setinsitu(insitu)
1548 varlist = vars()
1549 s = scantable(self._math._freqswitch(self))
1550 s._add_history("freq_switch", varlist)
1551 print_log()
1552 if insitu: self._assign(s)
1553 else: return s
1554
1555 def recalc_azel(self):
1556 """
1557 Recalculate the azimuth and elevation for each position.
1558 Parameters:
1559 none
1560 Example:
1561 """
1562 varlist = vars()
1563 self._recalcazel()
1564 self._add_history("recalc_azel", varlist)
1565 print_log()
1566 return
1567
1568 def __add__(self, other):
1569 varlist = vars()
1570 s = None
1571 if isinstance(other, scantable):
1572 s = scantable(self._math._binaryop(self, other, "ADD"))
1573 elif isinstance(other, float):
1574 s = scantable(self._math._unaryop(self, other, "ADD", False))
1575 else:
1576 raise TypeError("Other input is not a scantable or float value")
1577 s._add_history("operator +", varlist)
1578 print_log()
1579 return s
1580
1581 def __sub__(self, other):
1582 """
1583 implicit on all axes and on Tsys
1584 """
1585 varlist = vars()
1586 s = None
1587 if isinstance(other, scantable):
1588 s = scantable(self._math._binaryop(self, other, "SUB"))
1589 elif isinstance(other, float):
1590 s = scantable(self._math._unaryop(self, other, "SUB", False))
1591 else:
1592 raise TypeError("Other input is not a scantable or float value")
1593 s._add_history("operator -", varlist)
1594 print_log()
1595 return s
1596
1597 def __mul__(self, other):
1598 """
1599 implicit on all axes and on Tsys
1600 """
1601 varlist = vars()
1602 s = None
1603 if isinstance(other, scantable):
1604 s = scantable(self._math._binaryop(self, other, "MUL"))
1605 elif isinstance(other, float):
1606 s = scantable(self._math._unaryop(self, other, "MUL", False))
1607 else:
1608 raise TypeError("Other input is not a scantable or float value")
1609 s._add_history("operator *", varlist)
1610 print_log()
1611 return s
1612
1613
1614 def __div__(self, other):
1615 """
1616 implicit on all axes and on Tsys
1617 """
1618 varlist = vars()
1619 s = None
1620 if isinstance(other, scantable):
1621 s = scantable(self._math._binaryop(self, other, "DIV"))
1622 elif isinstance(other, float):
1623 if other == 0.0:
1624 raise ZeroDivisionError("Dividing by zero is not recommended")
1625 s = scantable(self._math._unaryop(self, other, "DIV", False))
1626 else:
1627 raise TypeError("Other input is not a scantable or float value")
1628 s._add_history("operator /", varlist)
1629 print_log()
1630 return s
1631
1632 def get_fit(self, row=0):
1633 """
1634 Print or return the stored fits for a row in the scantable
1635 Parameters:
1636 row: the row which the fit has been applied to.
1637 """
1638 if row > self.nrow():
1639 return
1640 from asap.asapfit import asapfit
1641 fit = asapfit(self._getfit(row))
1642 if rcParams['verbose']:
1643 print fit
1644 return
1645 else:
1646 return fit.as_dict()
1647
1648 def _add_history(self, funcname, parameters):
1649 # create date
1650 sep = "##"
1651 from datetime import datetime
1652 dstr = datetime.now().strftime('%Y/%m/%d %H:%M:%S')
1653 hist = dstr+sep
1654 hist += funcname+sep#cdate+sep
1655 if parameters.has_key('self'): del parameters['self']
1656 for k, v in parameters.iteritems():
1657 if type(v) is dict:
1658 for k2, v2 in v.iteritems():
1659 hist += k2
1660 hist += "="
1661 if isinstance(v2, scantable):
1662 hist += 'scantable'
1663 elif k2 == 'mask':
1664 if isinstance(v2, list) or isinstance(v2, tuple):
1665 hist += str(self._zip_mask(v2))
1666 else:
1667 hist += str(v2)
1668 else:
1669 hist += str(v2)
1670 else:
1671 hist += k
1672 hist += "="
1673 if isinstance(v, scantable):
1674 hist += 'scantable'
1675 elif k == 'mask':
1676 if isinstance(v, list) or isinstance(v, tuple):
1677 hist += str(self._zip_mask(v))
1678 else:
1679 hist += str(v)
1680 else:
1681 hist += str(v)
1682 hist += sep
1683 hist = hist[:-2] # remove trailing '##'
1684 self._addhistory(hist)
1685
1686
1687 def _zip_mask(self, mask):
1688 mask = list(mask)
1689 i = 0
1690 segments = []
1691 while mask[i:].count(1):
1692 i += mask[i:].index(1)
1693 if mask[i:].count(0):
1694 j = i + mask[i:].index(0)
1695 else:
1696 j = len(mask)
1697 segments.append([i, j])
1698 i = j
1699 return segments
1700
1701 def _get_ordinate_label(self):
1702 fu = "("+self.get_fluxunit()+")"
1703 import re
1704 lbl = "Intensity"
1705 if re.match(".K.", fu):
1706 lbl = "Brightness Temperature "+ fu
1707 elif re.match(".Jy.", fu):
1708 lbl = "Flux density "+ fu
1709 return lbl
1710
1711 def _check_ifs(self):
1712 nchans = [self.nchan(i) for i in range(self.nif(-1))]
1713 nchans = filter(lambda t: t > 0, nchans)
1714 return (sum(nchans)/len(nchans) == nchans[0])
1715
1716 def _fill(self, names, unit, average):
1717 import os
1718 from asap._asap import stfiller
1719 first = True
1720 fullnames = []
1721 for name in names:
1722 name = os.path.expandvars(name)
1723 name = os.path.expanduser(name)
1724 if not os.path.exists(name):
1725 msg = "File '%s' does not exists" % (name)
1726 if rcParams['verbose']:
1727 asaplog.push(msg)
1728 print asaplog.pop().strip()
1729 return
1730 raise IOError(msg)
1731 fullnames.append(name)
1732 if average:
1733 asaplog.push('Auto averaging integrations')
1734 stype = int(rcParams['scantable.storage'].lower() == 'disk')
1735 for name in fullnames:
1736 tbl = Scantable(stype)
1737 r = stfiller(tbl)
1738 msg = "Importing %s..." % (name)
1739 asaplog.push(msg, False)
1740 print_log()
1741 r._open(name, -1, -1)
1742 r._read()
1743 #tbl = r._getdata()
1744 if average:
1745 tbl = self._math._average((tbl, ), (), 'NONE', 'SCAN')
1746 #tbl = tbl2
1747 if not first:
1748 tbl = self._math._merge([self, tbl])
1749 #tbl = tbl2
1750 Scantable.__init__(self, tbl)
1751 r._close()
1752 del r, tbl
1753 first = False
1754 if unit is not None:
1755 self.set_fluxunit(unit)
1756 self.set_freqframe(rcParams['scantable.freqframe'])
1757
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