[101] | 1 | from scantable import scantable |
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[258] | 2 | from asap import rcParams |
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[101] | 3 | |
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[143] | 4 | def average_time(*args, **kwargs): |
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[101] | 5 | """ |
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[113] | 6 | Return the (time) average of a scan or list of scans. [in channels only] |
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[305] | 7 | The cursor of the output scan is set to 0 |
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[113] | 8 | Parameters: |
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| 9 | one scan or comma separated scans |
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[143] | 10 | mask: an optional mask (only used for 'var' and 'tsys' weighting) |
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| 11 | scanav: False (default) averages all scans together, |
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| 12 | True averages each scan separately |
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| 13 | weight: Weighting scheme. 'none' (default), 'var' (variance |
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| 14 | weighted), 'tsys' |
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[113] | 15 | Example: |
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| 16 | # return a time averaged scan from scana and scanb |
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| 17 | # without using a mask |
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[129] | 18 | scanav = average_time(scana,scanb) |
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[113] | 19 | # return the (time) averaged scan, i.e. the average of |
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| 20 | # all correlator cycles |
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| 21 | scanav = average_time(scan) |
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[143] | 22 | |
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[101] | 23 | """ |
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[143] | 24 | scanAv = False |
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| 25 | if kwargs.has_key('scanav'): |
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| 26 | scanAv = kwargs.get('scanav') |
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[258] | 27 | |
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[143] | 28 | weight = 'none' |
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| 29 | if kwargs.has_key('weight'): |
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| 30 | weight = kwargs.get('weight') |
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[258] | 31 | |
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[143] | 32 | mask = () |
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| 33 | if kwargs.has_key('mask'): |
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| 34 | mask = kwargs.get('mask') |
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[258] | 35 | |
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[143] | 36 | lst = tuple(args) |
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| 37 | from asap._asap import average as _av |
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[113] | 38 | for s in lst: |
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[101] | 39 | if not isinstance(s,scantable): |
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| 40 | print "Please give a list of scantables" |
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| 41 | return |
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[143] | 42 | return scantable(_av(lst, mask, scanAv, weight)) |
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[101] | 43 | |
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[245] | 44 | def quotient(source, reference, preserve=True): |
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[101] | 45 | """ |
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[246] | 46 | Return the quotient of a 'source' (signal) scan and a 'reference' scan. |
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| 47 | The reference can have just one row, even if the signal has many. Otherwise |
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| 48 | they must have the same number of rows. |
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[305] | 49 | The cursor of the output scan is set to 0 |
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[101] | 50 | Parameters: |
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| 51 | source: the 'on' scan |
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| 52 | reference: the 'off' scan |
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[245] | 53 | preserve: you can preserve (default) the continuum or |
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| 54 | remove it. The equations used are |
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| 55 | preserve - Output = Tref * (sig/ref) - Tref |
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| 56 | remove - Output = Tref * (sig/ref) - Tsig |
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[101] | 57 | """ |
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| 58 | from asap._asap import quotient as _quot |
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[245] | 59 | return scantable(_quot(source, reference, preserve)) |
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[101] | 60 | |
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[296] | 61 | def simple_math(left, right, op='add', tsys=True): |
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[242] | 62 | """ |
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| 63 | Apply simple mathematical binary operations to two |
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| 64 | scan tables, returning the result in a new scan table. |
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| 65 | The operation is applied to both the correlations and the TSys data |
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[305] | 66 | The cursor of the output scan is set to 0 |
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[242] | 67 | Parameters: |
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| 68 | left: the 'left' scan |
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| 69 | right: the 'right' scan |
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| 70 | op: the operation: 'add' (default), 'sub', 'mul', 'div' |
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[296] | 71 | tsys: if True (default) then apply the operation to Tsys |
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| 72 | as well as the data |
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[242] | 73 | """ |
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[258] | 74 | if not isinstance(left,scantable) and not isinstance(right,scantable): |
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| 75 | print "Please provide two scantables as input" |
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| 76 | return |
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[242] | 77 | from asap._asap import b_operate as _bop |
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[296] | 78 | return scantable(_bop(left, right, op, tsys)) |
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[242] | 79 | |
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[296] | 80 | def scale(scan, factor, insitu=None, allaxes=None, tsys=True): |
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[101] | 81 | """ |
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| 82 | Return a scan where all spectra are scaled by the give 'factor' |
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| 83 | Parameters: |
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| 84 | scan: a scantable |
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[113] | 85 | factor: the scaling factor |
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[258] | 86 | insitu: if False a new scantable is returned. |
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[150] | 87 | Otherwise, the scaling is done in-situ |
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[258] | 88 | The default is taken from .asaprc (False) |
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| 89 | allaxes: if True apply to all spectra. Otherwise |
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| 90 | apply only to the selected (beam/pol/if)spectra only. |
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| 91 | The default is taken from .asaprc (True) |
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[296] | 92 | tsys: if True (default) then apply the operation to Tsys |
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| 93 | as well as the data |
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[101] | 94 | """ |
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[258] | 95 | if allaxes is None: allaxes = rcParams['scantable.allaxes'] |
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| 96 | if insitu is None: insitu = rcParams['insitu'] |
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[141] | 97 | if not insitu: |
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| 98 | from asap._asap import scale as _scale |
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[296] | 99 | return scantable(_scale(scan, factor, allaxes, tsys)) |
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[141] | 100 | else: |
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| 101 | from asap._asap import scale_insitu as _scale |
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[296] | 102 | _scale(scan, factor, allaxes, tsys) |
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[141] | 103 | return |
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| 104 | |
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[101] | 105 | |
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[258] | 106 | def add(scan, offset, insitu=None, allaxes=None): |
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[113] | 107 | """ |
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[150] | 108 | Return a scan where all spectra have the offset added |
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[113] | 109 | Parameters: |
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| 110 | scan: a scantable |
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[150] | 111 | offset: the offset |
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[258] | 112 | insitu: if False a new scantable is returned. |
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| 113 | Otherwise, the scaling is done in-situ |
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| 114 | The default is taken from .asaprc (False) |
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| 115 | allaxes: if True apply to all spectra. Otherwise |
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[150] | 116 | apply only to the selected (beam/pol/if)spectra only |
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[258] | 117 | The default is taken from .asaprc (True) |
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[113] | 118 | """ |
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[258] | 119 | if allaxes is None: allaxes = rcParams['scantable.allaxes'] |
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| 120 | if insitu is None: insitu = rcParams['insitu'] |
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[150] | 121 | if not insitu: |
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| 122 | from asap._asap import add as _add |
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[258] | 123 | return scantable(_add(scan, offset, allaxes)) |
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[150] | 124 | else: |
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| 125 | from asap._asap import add_insitu as _add |
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[258] | 126 | _add(scan, offset, allaxes) |
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[150] | 127 | return |
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| 128 | |
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[258] | 129 | def convert_flux(scan, area, eta=1.0, insitu=None, allaxes=None): |
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[224] | 130 | """ |
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| 131 | Return a scan where all spectra are converted to either Jansky or Kelvin |
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| 132 | depending upon the flux units of the scan table. |
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| 133 | Parameters: |
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| 134 | scan: a scantable |
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| 135 | area: the illuminated area of the telescope (m**2) |
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| 136 | eta: The efficiency of the telescope (default 1.0) |
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[258] | 137 | insitu: if False a new scantable is returned. |
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| 138 | Otherwise, the scaling is done in-situ |
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| 139 | The default is taken from .asaprc (False) |
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| 140 | allaxes: if True apply to all spectra. Otherwise |
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[224] | 141 | apply only to the selected (beam/pol/if)spectra only |
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[258] | 142 | The default is taken from .asaprc (True) |
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[224] | 143 | """ |
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[258] | 144 | if allaxes is None: allaxes = rcParams['scantable.allaxes'] |
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| 145 | if insitu is None: insitu = rcParams['insitu'] |
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[224] | 146 | if not insitu: |
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| 147 | from asap._asap import convertflux as _convert |
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[258] | 148 | return scantable(_convert(scan, area, eta, allaxes)) |
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[224] | 149 | else: |
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| 150 | from asap._asap import convertflux_insitu as _convert |
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[258] | 151 | _convert(scan, area, eta, allaxes) |
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[224] | 152 | return |
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[229] | 153 | |
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[258] | 154 | def gain_el(scan, poly=None, filename="", method="linear", insitu=None, allaxes=None): |
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[229] | 155 | """ |
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[242] | 156 | Return a scan after applying a gain-elevation correction. The correction |
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| 157 | can be made via either a polynomial or a table-based interpolation |
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| 158 | (and extrapolation if necessary). |
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| 159 | You specify polynomial coefficients, an ascii table or neither. |
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| 160 | If you specify neither, then a polynomial correction will be made |
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| 161 | with built in coefficients known for certain telescopes (an error will |
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| 162 | occur if the instrument is not known). |
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[229] | 163 | Parameters: |
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| 164 | scan: a scantable |
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[258] | 165 | poly: Polynomial coefficients (default None) to compute a |
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| 166 | gain-elevation correction as a function of |
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| 167 | elevation (in degrees). |
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[242] | 168 | filename: The name of an ascii file holding correction factors. |
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| 169 | The first row of the ascii file must give the column |
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| 170 | names and these MUST include columns |
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[258] | 171 | "ELEVATION" (degrees) and "FACTOR" (multiply data by this) |
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| 172 | somewhere. |
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| 173 | The second row must give the data type of the column. Use |
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| 174 | 'R' for Real and 'I' for Integer. An example file |
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| 175 | would be: |
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[229] | 176 | |
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[242] | 177 | TIME ELEVATION FACTOR |
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| 178 | R R R |
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| 179 | 0.1 0 1.5 |
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| 180 | 0.2 20 1.4 |
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| 181 | 0.3 40 1.3 |
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| 182 | 0.4 60 1.2 |
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| 183 | 0.5 80 1.1 |
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| 184 | 0.6 90 1.0 |
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| 185 | method: Interpolation method when correcting from a table. Values |
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| 186 | are "nearest", "linear" (default), "cubic" and "spline" |
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[258] | 187 | insitu: if False a new scantable is returned. |
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| 188 | Otherwise, the scaling is done in-situ |
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| 189 | The default is taken from .asaprc (False) |
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| 190 | allaxes: if True apply to all spectra. Otherwise |
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| 191 | apply only to the selected (beam/pol/if) spectra only |
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| 192 | The default is taken from .asaprc (True) |
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[229] | 193 | """ |
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[258] | 194 | if allaxes is None: allaxes = rcParams['scantable.allaxes'] |
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[242] | 195 | if poly is None: |
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| 196 | poly = () |
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[258] | 197 | if insitu is None: insitu = rcParams['insitu'] |
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[229] | 198 | if not insitu: |
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| 199 | from asap._asap import gainel as _gainEl |
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[258] | 200 | return scantable(_gainEl(scan, poly, filename, method, allaxes)) |
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[229] | 201 | else: |
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| 202 | from asap._asap import gainel_insitu as _gainEl |
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[258] | 203 | _gainEl(scan, poly, filename, method, allaxes) |
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[229] | 204 | return |
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[224] | 205 | |
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[319] | 206 | def freq_align(scan, reftime=None, method='cubic', insitu=None): |
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[269] | 207 | """ |
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[313] | 208 | Return a scan where all rows have been aligned in frequency. The |
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| 209 | alignment frequency frame (e.g. LSRK) is that set by function |
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| 210 | set_freqframe. |
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[269] | 211 | scan: a scantable |
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[273] | 212 | reftime: reference time to align at. By default, the time of |
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| 213 | the first row of data is used. |
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[319] | 214 | method: Interpolation method for regridding the spectra. Choose |
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| 215 | from "nearest", "linear", "cubic" (default) and "spline" |
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[269] | 216 | insitu: if False a new scantable is returned. |
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| 217 | Otherwise, the scaling is done in-situ |
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| 218 | The default is taken from .asaprc (False) |
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| 219 | """ |
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[273] | 220 | if reftime is None: reftime = '' |
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[269] | 221 | if insitu is None: insitu = rcParams['insitu'] |
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| 222 | if not insitu: |
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[313] | 223 | from asap._asap import freq_align as _align |
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[319] | 224 | return scantable(_align(scan, reftime, method)) |
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[269] | 225 | else: |
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[313] | 226 | from asap._asap import freq_align_insitu as _align |
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[319] | 227 | _align(scan, reftime, method) |
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[269] | 228 | return |
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| 229 | |
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[258] | 230 | def opacity(scan, tau, insitu=None, allaxes=None): |
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[242] | 231 | """ |
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| 232 | Return a scan after applying an opacity correction. |
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| 233 | Parameters: |
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| 234 | scan: a scantable |
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| 235 | tau: Opacity from which the correction factor is exp(tau*ZD) |
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| 236 | where ZD is the zenith-distance |
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[258] | 237 | insitu: if False a new scantable is returned. |
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| 238 | Otherwise, the scaling is done in-situ |
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| 239 | The default is taken from .asaprc (False) |
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| 240 | allaxes: if True apply to all spectra. Otherwise |
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[242] | 241 | apply only to the selected (beam/pol/if)spectra only |
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[258] | 242 | The default is taken from .asaprc (True) |
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[242] | 243 | """ |
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[258] | 244 | if allaxes is None: allaxes = rcParams['scantable.allaxes'] |
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| 245 | if insitu is None: insitu = rcParams['insitu'] |
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[242] | 246 | if not insitu: |
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| 247 | from asap._asap import opacity as _opacity |
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[258] | 248 | return scantable(_opacity(scan, tau, allaxes)) |
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[242] | 249 | else: |
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| 250 | from asap._asap import opacity_insitu as _opacity |
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[258] | 251 | _opacity(scan, tau, allaxes) |
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[242] | 252 | return |
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| 253 | |
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[258] | 254 | def bin(scan, width=5, insitu=None): |
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[101] | 255 | """ |
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[167] | 256 | Return a scan where all spectra have been binned up |
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[172] | 257 | width: The bin width (default=5) in pixels |
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[258] | 258 | insitu: if False a new scantable is returned. |
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| 259 | Otherwise, the scaling is done in-situ |
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| 260 | The default is taken from .asaprc (False) |
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[101] | 261 | """ |
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[258] | 262 | if insitu is None: insitu = rcParams['insitu'] |
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[167] | 263 | if not insitu: |
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| 264 | from asap._asap import bin as _bin |
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| 265 | return scantable(_bin(scan, width)) |
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| 266 | else: |
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| 267 | from asap._asap import bin_insitu as _bin |
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| 268 | _bin(scan, width) |
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| 269 | return |
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[113] | 270 | |
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[301] | 271 | def resample(scan, width=5, method='cubic', insitu=None): |
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| 272 | """ |
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| 273 | Return a scan where all spectra have been binned up |
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| 274 | width: The bin width (default=5) in pixels |
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| 275 | method: Interpolation method when correcting from a table. Values |
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| 276 | are "nearest", "linear", "cubic" (default) and "spline" |
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| 277 | insitu: if False a new scantable is returned. |
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| 278 | Otherwise, the scaling is done in-situ |
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| 279 | The default is taken from .asaprc (False) |
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| 280 | """ |
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| 281 | if insitu is None: insitu = rcParams['insitu'] |
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| 282 | if not insitu: |
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| 283 | from asap._asap import resample as _resample |
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| 284 | return scantable(_resample(scan, method, width)) |
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| 285 | else: |
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| 286 | from asap._asap import resample_insitu as _resample |
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| 287 | _resample(scan, method, width) |
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| 288 | return |
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| 289 | |
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[316] | 290 | def average_pol(scan, mask=None, weight='none', insitu=None): |
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[113] | 291 | """ |
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| 292 | Average the Polarisations together. |
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[305] | 293 | The polarisation cursor of the output scan is set to 0 |
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[113] | 294 | Parameters: |
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[172] | 295 | scan: The scantable |
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| 296 | mask: An optional mask defining the region, where the |
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| 297 | averaging will be applied. The output will have all |
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| 298 | specified points masked. |
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[316] | 299 | weight: Weighting scheme. 'none' (default), or 'var' (variance |
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| 300 | weighted) |
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[258] | 301 | insitu: if False a new scantable is returned. |
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| 302 | Otherwise, the scaling is done in-situ |
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| 303 | The default is taken from .asaprc (False) |
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[113] | 304 | Example: |
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| 305 | polav = average_pols(myscan) |
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| 306 | """ |
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| 307 | if mask is None: |
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[166] | 308 | mask = () |
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[258] | 309 | if insitu is None: insitu = rcParams['insitu'] |
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[166] | 310 | if not insitu: |
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| 311 | from asap._asap import averagepol as _avpol |
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[316] | 312 | return scantable(_avpol(scan, mask, weight)) |
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[166] | 313 | else: |
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| 314 | from asap._asap import averagepol_insitu as _avpol |
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[316] | 315 | _avpol(scan, mask, weight) |
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[166] | 316 | return |
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[113] | 317 | |
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[258] | 318 | def smooth(scan, kernel="hanning", width=5.0, insitu=None, allaxes=None): |
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[113] | 319 | """ |
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[180] | 320 | Smooth the spectrum by the specified kernel (conserving flux). |
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[113] | 321 | Parameters: |
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[172] | 322 | scan: The input scan |
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[180] | 323 | kernel: The type of smoothing kernel. Select from |
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| 324 | 'hanning' (default), 'gaussian' and 'boxcar'. |
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| 325 | The first three characters are sufficient. |
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| 326 | width: The width of the kernel in pixels. For hanning this is |
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| 327 | ignored otherwise it defauls to 5 pixels. |
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| 328 | For 'gaussian' it is the Full Width Half |
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| 329 | Maximum. For 'boxcar' it is the full width. |
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[258] | 330 | insitu: if False a new scantable is returned. |
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[172] | 331 | Otherwise, the scaling is done in-situ |
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[258] | 332 | The default is taken from .asaprc (False) |
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| 333 | allaxes: If True (default) apply to all spectra. Otherwise |
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[180] | 334 | apply only to the selected (beam/pol/if)spectra only |
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[258] | 335 | The default is taken from .asaprc (True) |
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[113] | 336 | Example: |
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| 337 | none |
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| 338 | """ |
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[258] | 339 | if allaxes is None: allaxes = rcParams['scantable.allaxes'] |
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| 340 | if insitu is None: insitu = rcParams['insitu'] |
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[172] | 341 | if not insitu: |
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[180] | 342 | from asap._asap import smooth as _smooth |
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[258] | 343 | return scantable(_smooth(scan,kernel,width,allaxes)) |
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[172] | 344 | else: |
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[180] | 345 | from asap._asap import smooth_insitu as _smooth |
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[258] | 346 | _smooth(scan,kernel,width,allaxes) |
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[172] | 347 | return |
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[113] | 348 | |
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[258] | 349 | def poly_baseline(scan, mask=None, order=0, insitu=None): |
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[113] | 350 | """ |
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[160] | 351 | Return a scan which has been baselined (all rows) by a polynomial. |
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[113] | 352 | Parameters: |
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| 353 | scan: a scantable |
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| 354 | mask: an optional mask |
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| 355 | order: the order of the polynomial (default is 0) |
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[258] | 356 | insitu: if False a new scantable is returned. |
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| 357 | Otherwise, the scaling is done in-situ |
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| 358 | The default is taken from .asaprc (False) |
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[113] | 359 | Example: |
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| 360 | # return a scan baselined by a third order polynomial, |
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| 361 | # not using a mask |
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| 362 | bscan = poly_baseline(scan, order=3) |
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| 363 | """ |
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| 364 | from asap.asapfitter import fitter |
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| 365 | if mask is None: |
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| 366 | from numarray import ones |
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| 367 | mask = tuple(ones(scan.nchan())) |
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| 368 | f = fitter() |
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| 369 | f._verbose(True) |
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| 370 | f.set_scan(scan, mask) |
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| 371 | f.set_function(poly=order) |
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[258] | 372 | sf = f.auto_fit(insitu) |
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[113] | 373 | return sf |
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