[101] | 1 | from scantable import scantable |
---|
[258] | 2 | from asap import rcParams |
---|
[101] | 3 | |
---|
[143] | 4 | def average_time(*args, **kwargs): |
---|
[101] | 5 | """ |
---|
[113] | 6 | Return the (time) average of a scan or list of scans. [in channels only] |
---|
| 7 | Parameters: |
---|
| 8 | one scan or comma separated scans |
---|
[143] | 9 | mask: an optional mask (only used for 'var' and 'tsys' weighting) |
---|
| 10 | scanav: False (default) averages all scans together, |
---|
| 11 | True averages each scan separately |
---|
| 12 | weight: Weighting scheme. 'none' (default), 'var' (variance |
---|
| 13 | weighted), 'tsys' |
---|
[113] | 14 | Example: |
---|
| 15 | # return a time averaged scan from scana and scanb |
---|
| 16 | # without using a mask |
---|
[129] | 17 | scanav = average_time(scana,scanb) |
---|
[113] | 18 | # return the (time) averaged scan, i.e. the average of |
---|
| 19 | # all correlator cycles |
---|
| 20 | scanav = average_time(scan) |
---|
[143] | 21 | |
---|
[101] | 22 | """ |
---|
[143] | 23 | scanAv = False |
---|
| 24 | if kwargs.has_key('scanav'): |
---|
| 25 | scanAv = kwargs.get('scanav') |
---|
[258] | 26 | |
---|
[143] | 27 | weight = 'none' |
---|
| 28 | if kwargs.has_key('weight'): |
---|
| 29 | weight = kwargs.get('weight') |
---|
[258] | 30 | |
---|
[143] | 31 | mask = () |
---|
| 32 | if kwargs.has_key('mask'): |
---|
| 33 | mask = kwargs.get('mask') |
---|
[258] | 34 | |
---|
[143] | 35 | lst = tuple(args) |
---|
| 36 | from asap._asap import average as _av |
---|
[113] | 37 | for s in lst: |
---|
[101] | 38 | if not isinstance(s,scantable): |
---|
| 39 | print "Please give a list of scantables" |
---|
| 40 | return |
---|
[143] | 41 | return scantable(_av(lst, mask, scanAv, weight)) |
---|
[101] | 42 | |
---|
[245] | 43 | def quotient(source, reference, preserve=True): |
---|
[101] | 44 | """ |
---|
[246] | 45 | Return the quotient of a 'source' (signal) scan and a 'reference' scan. |
---|
| 46 | The reference can have just one row, even if the signal has many. Otherwise |
---|
| 47 | they must have the same number of rows. |
---|
[101] | 48 | Parameters: |
---|
| 49 | source: the 'on' scan |
---|
| 50 | reference: the 'off' scan |
---|
[245] | 51 | preserve: you can preserve (default) the continuum or |
---|
| 52 | remove it. The equations used are |
---|
| 53 | preserve - Output = Tref * (sig/ref) - Tref |
---|
| 54 | remove - Output = Tref * (sig/ref) - Tsig |
---|
[101] | 55 | """ |
---|
| 56 | from asap._asap import quotient as _quot |
---|
[245] | 57 | return scantable(_quot(source, reference, preserve)) |
---|
[101] | 58 | |
---|
[258] | 59 | def simple_math(left, right, op='add'): |
---|
[242] | 60 | """ |
---|
| 61 | Apply simple mathematical binary operations to two |
---|
| 62 | scan tables, returning the result in a new scan table. |
---|
| 63 | The operation is applied to both the correlations and the TSys data |
---|
| 64 | Parameters: |
---|
| 65 | left: the 'left' scan |
---|
| 66 | right: the 'right' scan |
---|
| 67 | op: the operation: 'add' (default), 'sub', 'mul', 'div' |
---|
| 68 | """ |
---|
[258] | 69 | if not isinstance(left,scantable) and not isinstance(right,scantable): |
---|
| 70 | print "Please provide two scantables as input" |
---|
| 71 | return |
---|
[242] | 72 | from asap._asap import b_operate as _bop |
---|
| 73 | return scantable(_bop(left, right, op)) |
---|
| 74 | |
---|
[258] | 75 | def scale(scan, factor, insitu=None, allaxes=None): |
---|
[101] | 76 | """ |
---|
| 77 | Return a scan where all spectra are scaled by the give 'factor' |
---|
| 78 | Parameters: |
---|
| 79 | scan: a scantable |
---|
[113] | 80 | factor: the scaling factor |
---|
[258] | 81 | insitu: if False a new scantable is returned. |
---|
[150] | 82 | Otherwise, the scaling is done in-situ |
---|
[258] | 83 | The default is taken from .asaprc (False) |
---|
| 84 | allaxes: if True apply to all spectra. Otherwise |
---|
| 85 | apply only to the selected (beam/pol/if)spectra only. |
---|
| 86 | The default is taken from .asaprc (True) |
---|
[101] | 87 | """ |
---|
[258] | 88 | if allaxes is None: allaxes = rcParams['scantable.allaxes'] |
---|
| 89 | if insitu is None: insitu = rcParams['insitu'] |
---|
[141] | 90 | if not insitu: |
---|
| 91 | from asap._asap import scale as _scale |
---|
[258] | 92 | return scantable(_scale(scan, factor, allaxes)) |
---|
[141] | 93 | else: |
---|
| 94 | from asap._asap import scale_insitu as _scale |
---|
[258] | 95 | _scale(scan, factor, allaxes) |
---|
[141] | 96 | return |
---|
| 97 | |
---|
[101] | 98 | |
---|
[258] | 99 | def add(scan, offset, insitu=None, allaxes=None): |
---|
[113] | 100 | """ |
---|
[150] | 101 | Return a scan where all spectra have the offset added |
---|
[113] | 102 | Parameters: |
---|
| 103 | scan: a scantable |
---|
[150] | 104 | offset: the offset |
---|
[258] | 105 | insitu: if False a new scantable is returned. |
---|
| 106 | Otherwise, the scaling is done in-situ |
---|
| 107 | The default is taken from .asaprc (False) |
---|
| 108 | allaxes: if True apply to all spectra. Otherwise |
---|
[150] | 109 | apply only to the selected (beam/pol/if)spectra only |
---|
[258] | 110 | The default is taken from .asaprc (True) |
---|
[113] | 111 | """ |
---|
[258] | 112 | if allaxes is None: allaxes = rcParams['scantable.allaxes'] |
---|
| 113 | if insitu is None: insitu = rcParams['insitu'] |
---|
[150] | 114 | if not insitu: |
---|
| 115 | from asap._asap import add as _add |
---|
[258] | 116 | return scantable(_add(scan, offset, allaxes)) |
---|
[150] | 117 | else: |
---|
| 118 | from asap._asap import add_insitu as _add |
---|
[258] | 119 | _add(scan, offset, allaxes) |
---|
[150] | 120 | return |
---|
| 121 | |
---|
[258] | 122 | def convert_flux(scan, area, eta=1.0, insitu=None, allaxes=None): |
---|
[224] | 123 | """ |
---|
| 124 | Return a scan where all spectra are converted to either Jansky or Kelvin |
---|
| 125 | depending upon the flux units of the scan table. |
---|
| 126 | Parameters: |
---|
| 127 | scan: a scantable |
---|
| 128 | area: the illuminated area of the telescope (m**2) |
---|
| 129 | eta: The efficiency of the telescope (default 1.0) |
---|
[258] | 130 | insitu: if False a new scantable is returned. |
---|
| 131 | Otherwise, the scaling is done in-situ |
---|
| 132 | The default is taken from .asaprc (False) |
---|
| 133 | allaxes: if True apply to all spectra. Otherwise |
---|
[224] | 134 | apply only to the selected (beam/pol/if)spectra only |
---|
[258] | 135 | The default is taken from .asaprc (True) |
---|
[224] | 136 | """ |
---|
[258] | 137 | if allaxes is None: allaxes = rcParams['scantable.allaxes'] |
---|
| 138 | if insitu is None: insitu = rcParams['insitu'] |
---|
[224] | 139 | if not insitu: |
---|
| 140 | from asap._asap import convertflux as _convert |
---|
[258] | 141 | return scantable(_convert(scan, area, eta, allaxes)) |
---|
[224] | 142 | else: |
---|
| 143 | from asap._asap import convertflux_insitu as _convert |
---|
[258] | 144 | _convert(scan, area, eta, allaxes) |
---|
[224] | 145 | return |
---|
[229] | 146 | |
---|
[258] | 147 | def gain_el(scan, poly=None, filename="", method="linear", insitu=None, allaxes=None): |
---|
[229] | 148 | """ |
---|
[242] | 149 | Return a scan after applying a gain-elevation correction. The correction |
---|
| 150 | can be made via either a polynomial or a table-based interpolation |
---|
| 151 | (and extrapolation if necessary). |
---|
| 152 | You specify polynomial coefficients, an ascii table or neither. |
---|
| 153 | If you specify neither, then a polynomial correction will be made |
---|
| 154 | with built in coefficients known for certain telescopes (an error will |
---|
| 155 | occur if the instrument is not known). |
---|
[229] | 156 | Parameters: |
---|
| 157 | scan: a scantable |
---|
[258] | 158 | poly: Polynomial coefficients (default None) to compute a |
---|
| 159 | gain-elevation correction as a function of |
---|
| 160 | elevation (in degrees). |
---|
[242] | 161 | filename: The name of an ascii file holding correction factors. |
---|
| 162 | The first row of the ascii file must give the column |
---|
| 163 | names and these MUST include columns |
---|
[258] | 164 | "ELEVATION" (degrees) and "FACTOR" (multiply data by this) |
---|
| 165 | somewhere. |
---|
| 166 | The second row must give the data type of the column. Use |
---|
| 167 | 'R' for Real and 'I' for Integer. An example file |
---|
| 168 | would be: |
---|
[229] | 169 | |
---|
[242] | 170 | TIME ELEVATION FACTOR |
---|
| 171 | R R R |
---|
| 172 | 0.1 0 1.5 |
---|
| 173 | 0.2 20 1.4 |
---|
| 174 | 0.3 40 1.3 |
---|
| 175 | 0.4 60 1.2 |
---|
| 176 | 0.5 80 1.1 |
---|
| 177 | 0.6 90 1.0 |
---|
| 178 | method: Interpolation method when correcting from a table. Values |
---|
| 179 | are "nearest", "linear" (default), "cubic" and "spline" |
---|
[258] | 180 | insitu: if False a new scantable is returned. |
---|
| 181 | Otherwise, the scaling is done in-situ |
---|
| 182 | The default is taken from .asaprc (False) |
---|
| 183 | allaxes: if True apply to all spectra. Otherwise |
---|
| 184 | apply only to the selected (beam/pol/if) spectra only |
---|
| 185 | The default is taken from .asaprc (True) |
---|
[229] | 186 | """ |
---|
[258] | 187 | if allaxes is None: allaxes = rcParams['scantable.allaxes'] |
---|
[242] | 188 | if poly is None: |
---|
| 189 | poly = () |
---|
[258] | 190 | if insitu is None: insitu = rcParams['insitu'] |
---|
[229] | 191 | if not insitu: |
---|
| 192 | from asap._asap import gainel as _gainEl |
---|
[258] | 193 | return scantable(_gainEl(scan, poly, filename, method, allaxes)) |
---|
[229] | 194 | else: |
---|
| 195 | from asap._asap import gainel_insitu as _gainEl |
---|
[258] | 196 | _gainEl(scan, poly, filename, method, allaxes) |
---|
[229] | 197 | return |
---|
[224] | 198 | |
---|
[258] | 199 | def opacity(scan, tau, insitu=None, allaxes=None): |
---|
[242] | 200 | """ |
---|
| 201 | Return a scan after applying an opacity correction. |
---|
| 202 | Parameters: |
---|
| 203 | scan: a scantable |
---|
| 204 | tau: Opacity from which the correction factor is exp(tau*ZD) |
---|
| 205 | where ZD is the zenith-distance |
---|
[258] | 206 | insitu: if False a new scantable is returned. |
---|
| 207 | Otherwise, the scaling is done in-situ |
---|
| 208 | The default is taken from .asaprc (False) |
---|
| 209 | allaxes: if True apply to all spectra. Otherwise |
---|
[242] | 210 | apply only to the selected (beam/pol/if)spectra only |
---|
[258] | 211 | The default is taken from .asaprc (True) |
---|
[242] | 212 | """ |
---|
[258] | 213 | if allaxes is None: allaxes = rcParams['scantable.allaxes'] |
---|
| 214 | if insitu is None: insitu = rcParams['insitu'] |
---|
[242] | 215 | if not insitu: |
---|
| 216 | from asap._asap import opacity as _opacity |
---|
[258] | 217 | return scantable(_opacity(scan, tau, allaxes)) |
---|
[242] | 218 | else: |
---|
| 219 | from asap._asap import opacity_insitu as _opacity |
---|
[258] | 220 | _opacity(scan, tau, allaxes) |
---|
[242] | 221 | return |
---|
| 222 | |
---|
[258] | 223 | def bin(scan, width=5, insitu=None): |
---|
[101] | 224 | """ |
---|
[167] | 225 | Return a scan where all spectra have been binned up |
---|
[172] | 226 | width: The bin width (default=5) in pixels |
---|
[258] | 227 | insitu: if False a new scantable is returned. |
---|
| 228 | Otherwise, the scaling is done in-situ |
---|
| 229 | The default is taken from .asaprc (False) |
---|
[101] | 230 | """ |
---|
[258] | 231 | if insitu is None: insitu = rcParams['insitu'] |
---|
[167] | 232 | if not insitu: |
---|
| 233 | from asap._asap import bin as _bin |
---|
| 234 | return scantable(_bin(scan, width)) |
---|
| 235 | else: |
---|
| 236 | from asap._asap import bin_insitu as _bin |
---|
| 237 | _bin(scan, width) |
---|
| 238 | return |
---|
[113] | 239 | |
---|
[258] | 240 | def average_pol(scan, mask=None, insitu=None): |
---|
[113] | 241 | """ |
---|
| 242 | Average the Polarisations together. |
---|
| 243 | Parameters: |
---|
[172] | 244 | scan: The scantable |
---|
| 245 | mask: An optional mask defining the region, where the |
---|
| 246 | averaging will be applied. The output will have all |
---|
| 247 | specified points masked. |
---|
[258] | 248 | insitu: if False a new scantable is returned. |
---|
| 249 | Otherwise, the scaling is done in-situ |
---|
| 250 | The default is taken from .asaprc (False) |
---|
[113] | 251 | Example: |
---|
| 252 | polav = average_pols(myscan) |
---|
| 253 | """ |
---|
| 254 | if mask is None: |
---|
[166] | 255 | mask = () |
---|
[258] | 256 | if insitu is None: insitu = rcParams['insitu'] |
---|
[166] | 257 | if not insitu: |
---|
| 258 | from asap._asap import averagepol as _avpol |
---|
| 259 | return scantable(_avpol(scan, mask)) |
---|
| 260 | else: |
---|
| 261 | from asap._asap import averagepol_insitu as _avpol |
---|
| 262 | _avpol(scan, mask) |
---|
| 263 | return |
---|
[113] | 264 | |
---|
[258] | 265 | def smooth(scan, kernel="hanning", width=5.0, insitu=None, allaxes=None): |
---|
[113] | 266 | """ |
---|
[180] | 267 | Smooth the spectrum by the specified kernel (conserving flux). |
---|
[113] | 268 | Parameters: |
---|
[172] | 269 | scan: The input scan |
---|
[180] | 270 | kernel: The type of smoothing kernel. Select from |
---|
| 271 | 'hanning' (default), 'gaussian' and 'boxcar'. |
---|
| 272 | The first three characters are sufficient. |
---|
| 273 | width: The width of the kernel in pixels. For hanning this is |
---|
| 274 | ignored otherwise it defauls to 5 pixels. |
---|
| 275 | For 'gaussian' it is the Full Width Half |
---|
| 276 | Maximum. For 'boxcar' it is the full width. |
---|
[258] | 277 | insitu: if False a new scantable is returned. |
---|
[172] | 278 | Otherwise, the scaling is done in-situ |
---|
[258] | 279 | The default is taken from .asaprc (False) |
---|
| 280 | allaxes: If True (default) apply to all spectra. Otherwise |
---|
[180] | 281 | apply only to the selected (beam/pol/if)spectra only |
---|
[258] | 282 | The default is taken from .asaprc (True) |
---|
[113] | 283 | Example: |
---|
| 284 | none |
---|
| 285 | """ |
---|
[258] | 286 | if allaxes is None: allaxes = rcParams['scantable.allaxes'] |
---|
| 287 | if insitu is None: insitu = rcParams['insitu'] |
---|
[172] | 288 | if not insitu: |
---|
[180] | 289 | from asap._asap import smooth as _smooth |
---|
[258] | 290 | return scantable(_smooth(scan,kernel,width,allaxes)) |
---|
[172] | 291 | else: |
---|
[180] | 292 | from asap._asap import smooth_insitu as _smooth |
---|
[258] | 293 | _smooth(scan,kernel,width,allaxes) |
---|
[172] | 294 | return |
---|
[113] | 295 | |
---|
[258] | 296 | def poly_baseline(scan, mask=None, order=0, insitu=None): |
---|
[113] | 297 | """ |
---|
[160] | 298 | Return a scan which has been baselined (all rows) by a polynomial. |
---|
[113] | 299 | Parameters: |
---|
| 300 | scan: a scantable |
---|
| 301 | mask: an optional mask |
---|
| 302 | order: the order of the polynomial (default is 0) |
---|
[258] | 303 | insitu: if False a new scantable is returned. |
---|
| 304 | Otherwise, the scaling is done in-situ |
---|
| 305 | The default is taken from .asaprc (False) |
---|
[113] | 306 | Example: |
---|
| 307 | # return a scan baselined by a third order polynomial, |
---|
| 308 | # not using a mask |
---|
| 309 | bscan = poly_baseline(scan, order=3) |
---|
| 310 | """ |
---|
| 311 | from asap.asapfitter import fitter |
---|
| 312 | if mask is None: |
---|
| 313 | from numarray import ones |
---|
| 314 | mask = tuple(ones(scan.nchan())) |
---|
| 315 | f = fitter() |
---|
| 316 | f._verbose(True) |
---|
| 317 | f.set_scan(scan, mask) |
---|
| 318 | f.set_function(poly=order) |
---|
[258] | 319 | sf = f.auto_fit(insitu) |
---|
[113] | 320 | return sf |
---|