[101] | 1 | from scantable import scantable
|
---|
| 2 |
|
---|
[143] | 3 | def average_time(*args, **kwargs):
|
---|
[101] | 4 | """
|
---|
[113] | 5 | Return the (time) average of a scan or list of scans. [in channels only]
|
---|
| 6 | Parameters:
|
---|
| 7 | one scan or comma separated scans
|
---|
[143] | 8 | mask: an optional mask (only used for 'var' and 'tsys' weighting)
|
---|
| 9 | scanav: False (default) averages all scans together,
|
---|
| 10 | True averages each scan separately
|
---|
| 11 | weight: Weighting scheme. 'none' (default), 'var' (variance
|
---|
| 12 | weighted), 'tsys'
|
---|
[113] | 13 | Example:
|
---|
| 14 | # return a time averaged scan from scana and scanb
|
---|
| 15 | # without using a mask
|
---|
[129] | 16 | scanav = average_time(scana,scanb)
|
---|
[113] | 17 | # return the (time) averaged scan, i.e. the average of
|
---|
| 18 | # all correlator cycles
|
---|
| 19 | scanav = average_time(scan)
|
---|
[143] | 20 |
|
---|
[101] | 21 | """
|
---|
[143] | 22 | scanAv = False
|
---|
| 23 | if kwargs.has_key('scanav'):
|
---|
| 24 | scanAv = kwargs.get('scanav')
|
---|
| 25 | #
|
---|
| 26 | weight = 'none'
|
---|
| 27 | if kwargs.has_key('weight'):
|
---|
| 28 | weight = kwargs.get('weight')
|
---|
| 29 | #
|
---|
| 30 | mask = ()
|
---|
| 31 | if kwargs.has_key('mask'):
|
---|
| 32 | mask = kwargs.get('mask')
|
---|
| 33 | #
|
---|
| 34 | lst = tuple(args)
|
---|
| 35 | from asap._asap import average as _av
|
---|
[113] | 36 | for s in lst:
|
---|
[101] | 37 | if not isinstance(s,scantable):
|
---|
| 38 | print "Please give a list of scantables"
|
---|
| 39 | return
|
---|
[143] | 40 | return scantable(_av(lst, mask, scanAv, weight))
|
---|
[101] | 41 |
|
---|
| 42 | def quotient(source, reference):
|
---|
| 43 | """
|
---|
| 44 | Return the quotient of a 'source' scan and a 'reference' scan
|
---|
| 45 | Parameters:
|
---|
| 46 | source: the 'on' scan
|
---|
| 47 | reference: the 'off' scan
|
---|
| 48 | """
|
---|
| 49 | from asap._asap import quotient as _quot
|
---|
| 50 | return scantable(_quot(source, reference))
|
---|
| 51 |
|
---|
[150] | 52 | def scale(scan, factor, insitu=False, all=True):
|
---|
[101] | 53 | """
|
---|
| 54 | Return a scan where all spectra are scaled by the give 'factor'
|
---|
| 55 | Parameters:
|
---|
| 56 | scan: a scantable
|
---|
[113] | 57 | factor: the scaling factor
|
---|
[150] | 58 | insitu: if False (default) a new scantable is returned.
|
---|
| 59 | Otherwise, the scaling is done in-situ
|
---|
| 60 | all: if True (default) apply to all spectra. Otherwise
|
---|
| 61 | apply only to the selected (beam/pol/if)spectra only
|
---|
[101] | 62 | """
|
---|
[141] | 63 | if not insitu:
|
---|
| 64 | from asap._asap import scale as _scale
|
---|
[150] | 65 | return scantable(_scale(scan, factor, all))
|
---|
[141] | 66 | else:
|
---|
| 67 | from asap._asap import scale_insitu as _scale
|
---|
[150] | 68 | _scale(scan, factor, all)
|
---|
[141] | 69 | return
|
---|
| 70 |
|
---|
[101] | 71 |
|
---|
[150] | 72 | def add(scan, offset, insitu=False, all=True):
|
---|
[113] | 73 | """
|
---|
[150] | 74 | Return a scan where all spectra have the offset added
|
---|
[113] | 75 | Parameters:
|
---|
| 76 | scan: a scantable
|
---|
[150] | 77 | offset: the offset
|
---|
| 78 | insitu: if False (default) a new scantable is returned.
|
---|
| 79 | Otherwise, the addition is done in-situ
|
---|
| 80 | all: if True (default) apply to all spectra. Otherwise
|
---|
| 81 | apply only to the selected (beam/pol/if)spectra only
|
---|
[113] | 82 | """
|
---|
[150] | 83 | if not insitu:
|
---|
| 84 | from asap._asap import add as _add
|
---|
| 85 | return scantable(_add(scan, offset, all))
|
---|
| 86 | else:
|
---|
| 87 | from asap._asap import add_insitu as _add
|
---|
| 88 | _add(scan, offset, all)
|
---|
| 89 | return
|
---|
| 90 |
|
---|
[225] | 91 | def convert_flux(scan, area, eta=1.0, insitu=False, all=True):
|
---|
[224] | 92 | """
|
---|
| 93 | Return a scan where all spectra are converted to either Jansky or Kelvin
|
---|
| 94 | depending upon the flux units of the scan table.
|
---|
| 95 | Parameters:
|
---|
| 96 | scan: a scantable
|
---|
| 97 | area: the illuminated area of the telescope (m**2)
|
---|
| 98 | eta: The efficiency of the telescope (default 1.0)
|
---|
| 99 | insitu: if False (default) a new scantable is returned.
|
---|
| 100 | Otherwise, the conversion is done in-situ
|
---|
| 101 | all: if True (default) apply to all spectra. Otherwise
|
---|
| 102 | apply only to the selected (beam/pol/if)spectra only
|
---|
| 103 | """
|
---|
| 104 | if not insitu:
|
---|
| 105 | from asap._asap import convertflux as _convert
|
---|
| 106 | return scantable(_convert(scan, area, eta, all))
|
---|
| 107 | else:
|
---|
| 108 | from asap._asap import convertflux_insitu as _convert
|
---|
| 109 | _convert(scan, area, eta, all)
|
---|
| 110 | return
|
---|
[229] | 111 |
|
---|
| 112 | def gain_el(scan, filename="gainel.txt", method="linear", insitu=False, all=True):
|
---|
| 113 | """
|
---|
| 114 | Return a scan after applying a gain-elevation correction via interpolation
|
---|
| 115 | (and extrapolation if necessary) from values in an ascii file.
|
---|
| 116 | Parameters:
|
---|
| 117 | scan: a scantable
|
---|
| 118 | filename: The name of the ASCII file holding the data. The first row
|
---|
| 119 | must give the column names. These MUST include columns
|
---|
| 120 | "ELEVATION" (degrees) and "FACTOR" (multiply data by this) somewhere.
|
---|
| 121 | The second row must give the data type of the column. Use 'R' for
|
---|
| 122 | Real and 'I' for Integer. An example file would be:
|
---|
| 123 |
|
---|
| 124 | ELEVATION FACTOR
|
---|
| 125 | R R
|
---|
| 126 | 0 1.5
|
---|
| 127 | 20 1.4
|
---|
| 128 | 40 1.3
|
---|
| 129 | 60 1.2
|
---|
| 130 | 80 1.1
|
---|
| 131 | 90 1.0
|
---|
| 132 | method: Interpolation method. "nearest", "linear" (default),
|
---|
| 133 | "cubic" and "spline"
|
---|
| 134 | insitu: if False (default) a new scantable is returned.
|
---|
| 135 | Otherwise, the conversion is done in-situ
|
---|
| 136 | all: if True (default) apply to all spectra. Otherwise
|
---|
| 137 | apply only to the selected (beam/pol/if)spectra only
|
---|
| 138 | """
|
---|
| 139 | if not insitu:
|
---|
| 140 | from asap._asap import gainel as _gainEl
|
---|
| 141 | return scantable(_gainEl(scan, filename, method, all))
|
---|
| 142 | else:
|
---|
| 143 | from asap._asap import gainel_insitu as _gainEl
|
---|
| 144 | _gainEl(scan, filename, method, all)
|
---|
| 145 | return
|
---|
[224] | 146 |
|
---|
[167] | 147 | def bin(scan, width=5, insitu=False):
|
---|
[101] | 148 | """
|
---|
[167] | 149 | Return a scan where all spectra have been binned up
|
---|
[172] | 150 | width: The bin width (default=5) in pixels
|
---|
[167] | 151 | insitu: if False (default) a new scantable is returned.
|
---|
| 152 | Otherwise, the addition is done in-situ
|
---|
[101] | 153 | """
|
---|
[167] | 154 | if not insitu:
|
---|
| 155 | from asap._asap import bin as _bin
|
---|
| 156 | return scantable(_bin(scan, width))
|
---|
| 157 | else:
|
---|
| 158 | from asap._asap import bin_insitu as _bin
|
---|
| 159 | _bin(scan, width)
|
---|
| 160 | return
|
---|
[113] | 161 |
|
---|
[166] | 162 | def average_pol(scan, mask=None, insitu=False):
|
---|
[113] | 163 | """
|
---|
| 164 | Average the Polarisations together.
|
---|
| 165 | Parameters:
|
---|
[172] | 166 | scan: The scantable
|
---|
| 167 | mask: An optional mask defining the region, where the
|
---|
| 168 | averaging will be applied. The output will have all
|
---|
| 169 | specified points masked.
|
---|
| 170 | insitu: If False (default) a new scantable is returned.
|
---|
[166] | 171 | Otherwise, the averaging is done in-situ
|
---|
[113] | 172 | Example:
|
---|
| 173 | polav = average_pols(myscan)
|
---|
| 174 | """
|
---|
| 175 | if mask is None:
|
---|
[166] | 176 | mask = ()
|
---|
| 177 | if not insitu:
|
---|
| 178 | from asap._asap import averagepol as _avpol
|
---|
| 179 | return scantable(_avpol(scan, mask))
|
---|
| 180 | else:
|
---|
| 181 | from asap._asap import averagepol_insitu as _avpol
|
---|
| 182 | _avpol(scan, mask)
|
---|
| 183 | return
|
---|
[113] | 184 |
|
---|
[180] | 185 | def smooth(scan, kernel="hanning", width=5.0, insitu=False, all=True):
|
---|
[113] | 186 | """
|
---|
[180] | 187 | Smooth the spectrum by the specified kernel (conserving flux).
|
---|
[113] | 188 | Parameters:
|
---|
[172] | 189 | scan: The input scan
|
---|
[180] | 190 | kernel: The type of smoothing kernel. Select from
|
---|
| 191 | 'hanning' (default), 'gaussian' and 'boxcar'.
|
---|
| 192 | The first three characters are sufficient.
|
---|
| 193 | width: The width of the kernel in pixels. For hanning this is
|
---|
| 194 | ignored otherwise it defauls to 5 pixels.
|
---|
| 195 | For 'gaussian' it is the Full Width Half
|
---|
| 196 | Maximum. For 'boxcar' it is the full width.
|
---|
[172] | 197 | insitu: If False (default) a new scantable is returned.
|
---|
| 198 | Otherwise, the scaling is done in-situ
|
---|
[180] | 199 | all: If True (default) apply to all spectra. Otherwise
|
---|
| 200 | apply only to the selected (beam/pol/if)spectra only
|
---|
[113] | 201 | Example:
|
---|
| 202 | none
|
---|
| 203 | """
|
---|
[172] | 204 | if not insitu:
|
---|
[180] | 205 | from asap._asap import smooth as _smooth
|
---|
| 206 | return scantable(_smooth(scan,kernel,width,all))
|
---|
[172] | 207 | else:
|
---|
[180] | 208 | from asap._asap import smooth_insitu as _smooth
|
---|
| 209 | _smooth(scan,kernel,width,all)
|
---|
[172] | 210 | return
|
---|
[113] | 211 |
|
---|
| 212 | def poly_baseline(scan, mask=None, order=0):
|
---|
| 213 | """
|
---|
[160] | 214 | Return a scan which has been baselined (all rows) by a polynomial.
|
---|
[113] | 215 | Parameters:
|
---|
| 216 | scan: a scantable
|
---|
| 217 | mask: an optional mask
|
---|
| 218 | order: the order of the polynomial (default is 0)
|
---|
| 219 | Example:
|
---|
| 220 | # return a scan baselined by a third order polynomial,
|
---|
| 221 | # not using a mask
|
---|
| 222 | bscan = poly_baseline(scan, order=3)
|
---|
| 223 | """
|
---|
| 224 | from asap.asapfitter import fitter
|
---|
| 225 | if mask is None:
|
---|
| 226 | from numarray import ones
|
---|
| 227 | mask = tuple(ones(scan.nchan()))
|
---|
| 228 | f = fitter()
|
---|
| 229 | f._verbose(True)
|
---|
| 230 | f.set_scan(scan, mask)
|
---|
| 231 | f.set_function(poly=order)
|
---|
| 232 | sf = f.auto_fit()
|
---|
| 233 | return sf
|
---|