source: trunk/python/asapgrid.py @ 2421

Last change on this file since 2421 was 2421, checked in by Takeshi Nakazato, 12 years ago

New Development: No

JIRA Issue: Yes CAS-2816

Ready for Test: Yes

Interface Changes: No

What Interface Changed: Please list interface changes

Test Programs: List test programs

Put in Release Notes: Yes/No?

Module(s): Module Names change impacts.

Description: Describe your changes here...

Support to plot only 1 pixel result.

Default unit for cell size is changed to 'arcsec' (was 'arcmin').

File size: 14.3 KB
Line 
1import numpy
2from asap import rcParams
3from asap.scantable import scantable
4from asap.selector import selector
5from asap._asap import stgrid
6import pylab as pl
7from logging import asaplog
8
9class asapgrid:
10    """
11    The asapgrid class is defined to convolve data onto regular
12    spatial grid. Typical usage is as follows:
13
14       # create asapgrid instance with two input data
15       g = asapgrid( ['testimage1.asap','testimage2.asap'] )
16       # set IFNO if necessary
17       g.setIF( 0 )
18       # set POLNOs if necessary
19       g.setPolList( [0,1] )
20       # set SCANNOs if necessary
21       g.setScanList( [22,23,24] )
22       # define image with full specification
23       # you can skip some parameters (see help for defineImage)
24       g.defineImage( nx=12, ny=12, cellx='10arcsec', celly='10arcsec',
25                      center='J2000 10h10m10s -5d05m05s' )
26       # set convolution function
27       g.setFunc( func='sf', width=3 )
28       # enable min/max clipping
29       g.enableClip()
30       # or, disable min/max clipping
31       #g.disableClip()
32       # actual gridding
33       g.grid()
34       # save result
35       g.save( outfile='grid.asap' )
36       # plot result
37       g.plot( plotchan=1246, plotpol=-1, plotgrid=True, plotobs=True )
38    """
39    def __init__( self, infile ):
40        """
41        Create asapgrid instance.
42
43        infile -- input data as a string or string list if you want
44                  to grid more than one data at once. 
45        """
46        self.outfile = None
47        self.ifno = None
48        self.gridder = stgrid()
49        self.setData( infile )
50
51    def setData( self, infile ):
52        """
53        Set data to be processed.
54
55        infile -- input data as a string or string list if you want
56                  to grid more than one data at once. 
57        """
58        if isinstance( infile, str ):
59            self.gridder._setin( infile )
60        else:
61            self.gridder._setfiles( infile )
62        self.infile = infile
63
64    def setIF( self, ifno ):
65        """
66        Set IFNO to be processed. Currently, asapgrid allows to process
67        only one IFNO for one gridding run even if the data contains
68        multiple IFs. If you didn't specify IFNO, default value, which
69        is IFNO in the first spectrum, will be processed.
70
71        ifno -- IFNO to be processed.
72        """
73        self.ifno = ifno
74        self.gridder._setif( self.ifno )
75
76    def setPolList( self, pollist ):
77        """
78        Set list of polarization components you want to process.
79        If not specified, all POLNOs will be processed.
80
81        pollist -- list of POLNOs.
82        """
83        self.gridder._setpollist( pollist )
84
85    def setScanList( self, scanlist ):
86        """
87        Set list of scans you want to process. If not specified, all
88        scans will be processed.
89
90        scanlist -- list of SCANNOs.
91        """
92        self.gridder._setscanlist( scanlist )
93
94    def defineImage( self, nx=-1, ny=-1, cellx='', celly='', center='' ):
95        """
96        Define spatial grid.
97
98        First two parameters, nx and ny, define number of pixels of
99        the grid. If which of those is not specified, it will be set
100        to the same value as the other. If none of them are specified,
101        it will be determined from map extent and cell size.
102
103        Next two parameters, cellx and celly, define size of pixel.
104        You should set those parameters as string, which is constructed
105        numerical value and unit, e.g. '0.5arcmin', or numerical value.
106        If those values are specified as numerical value, their units
107        will be assumed to 'arcsec'. If which of those is not specified,
108        it will be set to the same value as the other. If none of them
109        are specified, it will be determined from map extent and number
110        of pixels, or set to '1arcmin' if neither nx nor ny is set.
111
112        The last parameter, center, define the central coordinate of
113        the grid. You should specify its value as a string, like,
114
115           'J2000 05h08m50s -16d23m30s'
116
117        or
118
119           'J2000 05:08:50 -16.23.30'
120
121        You can omit equinox when you specify center coordinate. In that
122        case, J2000 is assumed. If center is not specified, it will be
123        determined from the observed positions of input data.
124
125        nx -- number of pixels along x (R.A.) direction.
126        ny -- number of pixels along y (Dec.) direction.
127        cellx -- size of pixel in x (R.A.) direction.
128        celly -- size of pixel in y (Dec.) direction.
129        center -- central position of the grid.
130        """
131        if not isinstance( cellx, str ):
132            cellx = '%sarcsec'%(cellx)
133        if not isinstance( celly, str ):
134            celly = '%sarcsec'%(celly)
135        self.gridder._defineimage( nx, ny, cellx, celly, center )
136
137    def setFunc( self, func='box', width=-1 ):
138        """
139        Set convolution function. Possible options are 'box' (Box-car,
140        default), 'sf' (prolate spheroidal), and 'gauss' (Gaussian).
141        Width of convolution function can be set using width parameter.
142        By default (-1), width is automatically set depending on each
143        convolution function. Default values for width are:
144
145           'box': 1 pixel
146           'sf': 3 pixels
147           'gauss': 3 pixels (width is used as HWHM)
148
149        func -- Function type ('box', 'sf', 'gauss').
150        width -- Width of convolution function. Default (-1) is to
151                 choose pre-defined value for each convolution function.
152        """
153        self.gridder._setfunc( func, width )
154
155    def setWeight( self, weightType='uniform' ):
156        """
157        Set weight type. Possible options are 'uniform' (default),
158        'tint' (weight by integration time), 'tsys' (weight by
159        Tsys: 1/Tsys**2), and 'tintsys' (weight by integration time
160        as well as Tsys: tint/Tsys**2).
161
162        weightType -- weight type ('uniform', 'tint', 'tsys', 'tintsys')
163        """
164        self.gridder._setweight( weightType )
165
166    def enableClip( self ):
167        """
168        Enable min/max clipping.
169
170        By default, min/max clipping is disabled so that you should
171        call this method before actual gridding if you want to do
172        clipping.
173        """
174        self.gridder._enableclip()
175
176    def disableClip( self ):
177        """
178        Disable min/max clipping.
179        """
180        self.gridder._disableclip()
181
182    def grid( self ):
183        """
184        Actual gridding which will be done based on several user inputs.
185        """
186        self.gridder._grid()
187
188    def save( self, outfile='' ):
189        """
190        Save result. By default, output data name will be constructed
191        from first element of input data name list (e.g. 'input.asap.grid').
192
193        outfile -- output data name.
194        """
195        self.outfile = self.gridder._save( outfile )
196
197    def plot( self, plotchan=-1, plotpol=-1, plotobs=False, plotgrid=False ):
198        """
199        Plot gridded data.
200
201        plotchan -- Which channel you want to plot. Default (-1) is
202                    to average all the channels.
203        plotpol -- Which polarization component you want to plot.
204                   Default (-1) is to average all the polarization
205                   components.
206        plotobs -- Also plot observed position if True. Default
207                   is False. Setting True for large amount of spectra
208                   might be time consuming.
209        plotgrid -- Also plot grid center if True. Default is False.
210                    Setting True for large number of grids might be
211                    time consuming.
212        """
213        import time
214        t0=time.time()
215        # to load scantable on disk
216        storg = rcParams['scantable.storage']
217        rcParams['scantable.storage'] = 'disk'
218        plotter = _SDGridPlotter( self.infile, self.outfile, self.ifno )
219        plotter.plot( chan=plotchan, pol=plotpol, plotobs=plotobs, plotgrid=plotgrid )
220        # back to original setup
221        rcParams['scantable.storage'] = storg
222        t1=time.time()
223        asaplog.push('plot: elapsed time %s sec'%(t1-t0))
224        asaplog.post('DEBUG','asapgrid.plot')
225       
226class _SDGridPlotter:
227    def __init__( self, infile, outfile=None, ifno=-1 ):
228        if isinstance( infile, str ):
229            self.infile = [infile]
230        else:
231            self.infile = infile
232        self.outfile = outfile
233        if self.outfile is None:
234            self.outfile = self.infile[0].rstrip('/')+'.grid'
235        self.nx = -1
236        self.ny = -1
237        self.nchan = 0
238        self.npol = 0
239        self.pollist = []
240        self.cellx = 0.0
241        self.celly = 0.0
242        self.center = [0.0,0.0]
243        self.nonzero = [[0.0],[0.0]]
244        self.ifno = ifno
245        self.tablein = None
246        self.nrow = 0
247        self.blc = None
248        self.trc = None
249        self.get()
250
251    def get( self ):
252        s = scantable( self.outfile, average=False )
253        self.nchan = len(s._getspectrum(0))
254        nrow = s.nrow()
255        pols = numpy.ones( nrow, dtype=int )
256        for i in xrange(nrow):
257            pols[i] = s.getpol(i)
258        self.pollist, indices = numpy.unique( pols, return_inverse=True )
259        self.npol = len(self.pollist)
260        self.pollist = self.pollist[indices[:self.npol]]
261        #print 'pollist=',self.pollist
262        #print 'npol=',self.npol
263        #print 'nrow=',nrow
264
265        idx = 0
266        d0 = s.get_direction( 0 ).split()[-1]
267        while ( s.get_direction(self.npol*idx) is not None \
268                and s.get_direction(self.npol*idx).split()[-1] == d0 ):
269            idx += 1
270       
271        self.nx = idx
272        self.ny = nrow / (self.npol * idx )
273        #print 'nx,ny=',self.nx,self.ny
274
275        self.blc = s.get_directionval( 0 )
276        self.trc = s.get_directionval( nrow-self.npol )
277        #print self.blc
278        #print self.trc
279        if nrow > 1:
280            incrx = s.get_directionval( self.npol )
281            incry = s.get_directionval( self.nx*self.npol )
282        else:
283            incrx = [0.0,0.0]
284            incry = [0.0,0.0]
285        self.cellx = abs( self.blc[0] - incrx[0] )
286        self.celly = abs( self.blc[1] - incry[1] )
287        #print 'cellx,celly=',self.cellx,self.celly
288
289    def plot( self, chan=-1, pol=-1, plotobs=False, plotgrid=False ):
290        if pol < 0:
291            opt = 'averaged over pol'
292        else:
293            opt = 'pol %s'%(pol)
294        if type(chan) is list:
295            opt += ', averaged over channel %s-%s'%(chan[0],chan[1])
296        elif chan < 0:
297            opt += ', averaged over channel'
298        else:
299            opt += ', channel %s'%(chan)
300        data = self.getData( chan, pol )
301        title = 'Gridded Image (%s)'%(opt)
302        pl.figure(10)
303        pl.clf()
304        # plot grid position
305        if plotgrid:
306            x = numpy.arange(self.blc[0],self.trc[0]+0.5*self.cellx,self.cellx,dtype=float)
307            #print 'len(x)=',len(x)
308            #print 'x=',x
309            ybase = numpy.ones(self.nx,dtype=float)*self.blc[1]
310            #print 'len(ybase)=',len(ybase)
311            incr = self.celly
312            for iy in xrange(self.ny):
313                y = ybase + iy * incr
314                #print y
315                pl.plot(x,y,',',color='blue')
316        # plot observed position
317        if plotobs:
318            for i in xrange(len(self.infile)):
319                self.createTableIn( self.infile[i] )
320                irow = 0
321                while ( irow < self.nrow ):
322                    chunk = self.getPointingChunk( irow )
323                    #print chunk
324                    pl.plot(chunk[0],chunk[1],',',color='green')
325                    irow += chunk.shape[1]
326                    #print irow
327        # show image
328        extent=[self.blc[0]-0.5*self.cellx,
329                self.trc[0]+0.5*self.cellx,
330                self.blc[1]-0.5*self.celly,
331                self.trc[1]+0.5*self.celly]
332        deccorr = 1.0/numpy.cos(0.5*(self.blc[1]+self.trc[1]))
333        pl.imshow(data,extent=extent,origin='lower',interpolation='nearest')
334        pl.colorbar()
335        pl.xlabel('R.A. [rad]')
336        pl.ylabel('Dec. [rad]')
337        ax = pl.axes()
338        ax.set_aspect(deccorr)
339        pl.title( title )
340
341    def createTableIn( self, tab ):
342        del self.tablein
343        self.tablein = scantable( tab, average=False )
344        if self.ifno < 0:
345            ifno = self.tablein.getif(0)
346            print 'ifno=',ifno
347        else:
348            ifno = self.ifno
349        sel = selector()
350        sel.set_ifs( ifno )
351        self.tablein.set_selection( sel )
352        self.nchan = len(self.tablein._getspectrum(0))
353        self.nrow = self.tablein.nrow()
354        del sel
355       
356
357    def getPointingChunk( self, irow ):
358        numchunk = 1000
359        nrow = min( self.nrow-irow, numchunk )
360        #print 'nrow=',nrow
361        v = numpy.zeros( (2,nrow), dtype=float )
362        idx = 0
363        for i in xrange(irow,irow+nrow):
364            d = self.tablein.get_directionval( i )
365            v[0,idx] = d[0]
366            v[1,idx] = d[1]
367            idx += 1
368        return v
369
370    def getData( self, chan=-1, pol=-1 ):
371        if type(chan) == list:
372            spectra = self.__chanAverage(start=chan[0],end=chan[1])
373        elif chan == -1:
374            spectra = self.__chanAverage()
375        else:
376            spectra = self.__chanIndex( chan )
377        data = spectra.reshape( (self.npol,self.ny,self.nx) )
378        if pol == -1:
379            retval = data.mean(axis=0)
380        else:
381            retval = data[pol]
382        return retval
383
384    def __chanAverage( self, start=-1, end=-1 ):
385        s = scantable( self.outfile, average=False )
386        nrow = s.nrow()
387        spectra = numpy.zeros( (self.npol,nrow/self.npol), dtype=float )
388        irow = 0
389        sp = [0 for i in xrange(self.nchan)]
390        if start < 0:
391            start = 0
392        if end < 0:
393            end = self.nchan
394        for i in xrange(nrow/self.npol):
395            for ip in xrange(self.npol):
396                sp = s._getspectrum( irow )[start:end]
397                spectra[ip,i] = numpy.mean( sp )
398                irow += 1
399           
400        return spectra
401
402    def __chanIndex( self, idx ):
403        s = scantable( self.outfile, average=False )
404        nrow = s.nrow()
405        spectra = numpy.zeros( (self.npol,nrow/self.npol), dtype=float )
406        irow = 0
407        sp = [0 for i in xrange(self.nchan)]
408        for i in xrange(nrow/self.npol):
409            for ip in xrange(self.npol):
410                sp = s._getspectrum( irow )
411                spectra[ip,i] = sp[idx]
412                irow += 1
413        return spectra
414       
415           
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