Coverage for /wheeldirectory/casa-6.7.0-12-py3.10.el8/lib/py/lib/python3.10/site-packages/casatasks/msuvbin.py: 56%

1##################### generated by xml-casa (v2) from msuvbin.xml ################### 

2##################### 1b0767ff69d778776ecf7ddce14ced3c ############################## 

3from __future__ import absolute_import 

4import numpy 

5from casatools.typecheck import CasaValidator as _val_ctor 

6_pc = _val_ctor( ) 

7from casatools.coercetype import coerce as _coerce 

8from casatools.errors import create_error_string 

9from .private.task_msuvbin import msuvbin as _msuvbin_t 

10from casatasks.private.task_logging import start_log as _start_log 

11from casatasks.private.task_logging import end_log as _end_log 

12from casatasks.private.task_logging import except_log as _except_log 

13 

14class _msuvbin: 

15 """ 

16 msuvbin ---- grid the visibility data onto a defined uniform grid (in the form of an ms); multiple MS's can be done onto the same grid 

17 

18  

19 msuvbin is a uv gridding task. The use is for large volumes 

20 of data (from multiple epochs) that needs to be imaged into 

21 one image. One way of proceeding is to image the epochs and 

22 average them after wards. Rather than doing this averaging 

23 the visibilities on a common uv grid has several convenience 

24 advantages like easily doing the proper weighted averaging and imaging. 

25 If an output grid already exists and a second ms is gridded on the grid 

26 then the output grid parameters is ignored but the existant grid is used. 

27  

28  

29 

30 --------- parameter descriptions --------------------------------------------- 

31 

32 vis Name of input visibility file (MS) 

33 default: none; 

34 field Field selection of input ms; use mssel syntax 

35 spw Spw selection; mssel syntax 

36 taql TaQl string for data selection; the advance user can do 

37 sophisticated data selection; see http://casacore.github.io/casacore-notes/199.html 

38 outputvis name of output uvgrid; if it existant the data will be binned additively into 

39 that uvgrid (as long as the parameters match for the grid description). If the gridded ms 

40 exists 

41 and the gridding parameters do not match the ones with which the grid was made--- 

42 msuvbin will exit with an exception 

43 phasecenter phase center of uv grid; if empty it will default 

44 the first field selected in the input ms 

45 imsize Number of pixels 

46 example: 

47  

48 imsize = [350,250] 

49 imsize = 500 is equivalent to [500,500] 

50  

51 To take proper advantage of internal optimized FFT routines, the 

52 number of pixels must be even and factorizable by 2,3,5 only. 

53 To find the nearest optimal imsize to that desired by the user, please use the following tool method: 

54  

55 from casatools import synthesisutils 

56 su = synthesisutils() 

57 su.getOptimumSize(345)  

58 Output : 360 

59 cell pixel cell size defined in sky dimension 

60 This should be in the units of sky angle. Usually you want to have a pixel size that 

61 is smaller than the maximum resolution that can be expected from the data. 

62 ncorr number of correlations to store in grid 

63 if 1 is chosen and data have cross hands, then both XX and YY (or RR and LL) 

64 will be gridded on the same correlation plane (XX or RR as MS V2.0 does not support 

65 I as a correlation type). 

66 if 2 is chosen the parallel hands will be stored on independent grids for each frequency channel 

67 if 4 is chosen the all correlation type will be gridded independently. 

68 nchan Nunmber of spectral channels in the output grid 

69 start Frequency of first channel of grid. If left empty, it will try to use the 

70 lowest frequency in the selected data 

71 width Spectral channel width. If left empty the badwidth of the selected data will be divided by the nchan 

72 selected to determine the width of an output channel. This happens only when not output grid already exists. 

73 wproject Do wprojection correction while gridding. This should be used with care as it is known to have issues like perfomance 

74 and for Cotton-Schwab style cleaning. 

75 memfrac Limit fraction of RAM available to use. Default is half. 

76 mode when mode will transfer back flag from grid to input ms 

77 For this to work both the original ms and the gridded ms has to exist and the flags will be 

78 transferred from the gridded ms back to original ms. This is provided as a utility to 

79 msuvbinflagger task. 

80 flagbackup Backup flags before saving flags when using write_flags_back 

81 RETURNS void 

82 

83 --------- examples ----------------------------------------------------------- 

84 

85  

86  

87  

88  

89  

90 Keyword arguments: 

91 vis -- Name of input visibility file 

92 default: none; example: vis='ngc5921.ms' 

93 field -- Field name list 

94 default: '' ==> all 

95 field = '1328+307' specifies source '1328+307' 

96 field = '4' specified field with index 4 

97 spw -- Spw selection 

98 default: spw = '' (all spw) 

99 spw='2' 

100 taql --TaQl expression for data selection (see https://casacore.github.io/casacore-notes/199.html) 

101 default taql='' 

102 Example select all data where U > 1 m in the ms 

103 taql='UVW[0] > 1' 

104 outputvis -- name of output grid 

105 default: '' The user has to give something here 

106 phasecenter -- phasecenter of the grid 

107 default= '' 

108 phasecenter='J2000 18h03m04 -20d00m45.1' 

109 imsize -- number of pixels along the x and y axes of the grid 

110 default=100 

111 imsize=[1000, 1000] 

112 cell -- cellsize of the grid (given in sky units) 

113 default: '1arcsec' 

114 cell='0.1arcsec' 

115 ncorr -- number of correlation/polarization plane in uv grid (allowed 1, 2, 4) 

116 default: 1 

117 ncorr=4 

118 nchan -- number of spectral channel 

119 default: 1 

120 nchan=2000 

121 start -- frequency of the first channel 

122 default: ''; User has to give something useful here 

123 width -- spectral channel width 

124 default: '' 

125 wproject -- do wprojection correction while gridding 

126 default: False 

127 wproject=True 

128 memfrac -- control how much of computer's memory is available for gridding 

129 default=0.5 

130 memfrac=0.9 

131  

132  

133 

134 

135 """ 

136 

137 _info_group_ = """manipulation, imaging""" 

138 _info_desc_ = """grid the visibility data onto a defined uniform grid (in the form of an ms); multiple MS\'s can be done onto the same grid""" 

139 

140 def __call__( self, vis='', field='', spw='', taql='', outputvis='', phasecenter='', imsize=[ int(100) ], cell='1arcsec', ncorr=int(1), nchan=int(1), start='', width='', wproject=False, memfrac=float(0.5), mode='bin', flagbackup=False ): 

141 schema = {'vis': {'type': 'cStr', 'coerce': _coerce.to_str}, 'field': {'type': 'cStr', 'coerce': _coerce.to_str}, 'spw': {'type': 'cStr', 'coerce': _coerce.to_str}, 'taql': {'type': 'cStr', 'coerce': _coerce.to_str}, 'outputvis': {'type': 'cStr', 'coerce': _coerce.to_str}, 'phasecenter': {'type': 'cStr', 'coerce': _coerce.to_str}, 'imsize': {'anyof': [{'type': 'cInt'}, {'type': 'cIntVec', 'coerce': [_coerce.to_list,_coerce.to_intvec]}]}, 'cell': {'type': 'cStr', 'coerce': _coerce.to_str}, 'ncorr': {'type': 'cInt', 'allowed': [ 1, 2, 4 ]}, 'nchan': {'type': 'cInt'}, 'start': {'type': 'cStr', 'coerce': _coerce.to_str}, 'width': {'type': 'cStr', 'coerce': _coerce.to_str}, 'wproject': {'type': 'cBool' # <allowed> IS NOT ALLOWED FOR A PARAMETER OF TYPE bool 

142}, 'memfrac': {'type': 'cFloat', 'coerce': _coerce.to_float, 'min': 0.01, 'max': 0.99}, 'mode': {'type': 'cStr', 'coerce': _coerce.to_str, 'allowed': [ 'bin', 'write_flags_back' ]}, 'flagbackup': {'type': 'cBool'}} 

143 doc = {'vis': vis, 'field': field, 'spw': spw, 'taql': taql, 'outputvis': outputvis, 'phasecenter': phasecenter, 'imsize': imsize, 'cell': cell, 'ncorr': ncorr, 'nchan': nchan, 'start': start, 'width': width, 'wproject': wproject, 'memfrac': memfrac, 'mode': mode, 'flagbackup': flagbackup} 

144 assert _pc.validate(doc,schema), create_error_string(_pc.errors) 

145 _logging_state_ = _start_log( 'msuvbin', [ 'vis=' + repr(_pc.document['vis']), 'field=' + repr(_pc.document['field']), 'spw=' + repr(_pc.document['spw']), 'taql=' + repr(_pc.document['taql']), 'outputvis=' + repr(_pc.document['outputvis']), 'phasecenter=' + repr(_pc.document['phasecenter']), 'imsize=' + repr(_pc.document['imsize']), 'cell=' + repr(_pc.document['cell']), 'ncorr=' + repr(_pc.document['ncorr']), 'nchan=' + repr(_pc.document['nchan']), 'start=' + repr(_pc.document['start']), 'width=' + repr(_pc.document['width']), 'wproject=' + repr(_pc.document['wproject']), 'memfrac=' + repr(_pc.document['memfrac']), 'mode=' + repr(_pc.document['mode']), 'flagbackup=' + repr(_pc.document['flagbackup']) ] ) 

146 task_result = None 

147 try: 

148 task_result = _msuvbin_t( _pc.document['vis'], _pc.document['field'], _pc.document['spw'], _pc.document['taql'], _pc.document['outputvis'], _pc.document['phasecenter'], _pc.document['imsize'], _pc.document['cell'], _pc.document['ncorr'], _pc.document['nchan'], _pc.document['start'], _pc.document['width'], _pc.document['wproject'], _pc.document['memfrac'], _pc.document['mode'], _pc.document['flagbackup'] ) 

149 except Exception as exc: 

150 _except_log('msuvbin', exc) 

151 raise 

152 finally: 

153 task_result = _end_log( _logging_state_, 'msuvbin', task_result ) 

154 return task_result 

155 

156msuvbin = _msuvbin( ) 

157