Segments — Manages groups of line segments.¶
This module defines the Segments class.
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class
admit.util.Segments.Segments(st=None, en=None, nchan=None, startchan=0)[source]¶ Class to hold segments and convert them between different types.
Segments are defined by a beginning and ending channel (both inclusive). ADMIT gives special meaning to a segment, for example a line can be found within that segment, or a continuum has to be fitted in that segment (or group of segments).
Parameters: st : array like
Array like object containing either the full segment list (array of two element arrays containing the start and end channel numbers for each segment), or an array of starting channel numbers. Default: None.
en : array like
An array of the ending channel number corresponding to the starting channel numbers given in st. Leave as None if st contains the full listing. Default: None.
nchan : int
The number of channels in the spectrum that the segments refer to. This is used to construct the bit mask for tracking all segments. If left as None, no bitmask will be made. Default: None.
startchan : int
The starting channel number of the spectrum that the segments refer to. Must be >= 0. Default: 0.
Methods
append(item)Method to append a new segment to the current list chans([invert])Method to convert the bit mask into a string of channel ranges in CASA format. getchannels([invert])Method to return the current list of channel numbers in the bitmask getmask()Method to return the current bitmask getnchan()Method to return the number of channels in the current bit mask getsegments()Method to get the list of segments getsegmentsaslists()Method to get the list of segments getsegmentsastuples()Method to get the list of segments as tuples getstartchan()Method to get the starting channel number of the current bit mask limits()Method to return the channel range of the internal channel bit mask merge([other])Method to merge overlapping segments into one segment. pop()Method to pop, or remove and return, the last segment in the list recalcmask([test])Method to recalculate the bit mask based on the current segment list. remove(index)Method to remove a segment from the segment list setnchan(nchan)Method to set the number of channels in the internal channel bit mask setstartchan(chan)Method to set the starting channels number for the internal bit mask -
append(item)[source]¶ Method to append a new segment to the current list
Parameters: item : two element array
The new segment to append to the list
Returns: None
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chans(invert=False)[source]¶ Method to convert the bit mask into a string of channel ranges in CASA format. e.g. [3,10],[25,50] => “3~10;25~50”
Parameters: None Returns: string containing the formatted channel ranges
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getchannels(invert=False)[source]¶ Method to return the current list of channel numbers in the bitmask
Parameters: invert : boolean
Return the list of channels outside the bitmask instead
Returns: Array like object containing the (zero based) channel numbers that are in the segments
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getmask()[source]¶ Method to return the current bitmask
Parameters: None Returns: Array like object containing the bit current bit mask, 1 = in segment, 0 = not in segment
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getnchan()[source]¶ Method to return the number of channels in the current bit mask
Parameters: None Returns: int giving the number of channels
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getsegments()[source]¶ Method to get the list of segments
Parameters: None Returns: list of the segment end points [start, end]
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getsegmentsaslists()[source]¶ Method to get the list of segments
Parameters: None Returns: list of the segment end points [start, end]
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getsegmentsastuples()[source]¶ Method to get the list of segments as tuples
Parameters: None Returns: list of the segment end points as tuples (start, end)
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getstartchan()[source]¶ Method to get the starting channel number of the current bit mask
Parameters: None Returns: int containing the starting channel number
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limits()[source]¶ Method to return the channel range of the internal channel bit mask
Parameters: None Returns: Array like 2 element list of the segment starting and ending channels
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merge(other=None)[source]¶ Method to merge overlapping segments into one segment. This operates on the current instance or takes a second instance or list of segments as input.
Parameters: other : Segments instance or list of segments
If given then these segments are added to the current list and then merged, to give a single list of non-overlapping segments.
Returns: None
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pop()[source]¶ Method to pop, or remove and return, the last segment in the list
Parameters: None
Returns: Array like 2 element list of the segment starting and ending channels of the last
segment in the list
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recalcmask(test=False)[source]¶ Method to recalculate the bit mask based on the current segment list. 1 = in segment 0 = not in segment
Parameters: test : bool
If True then test each segment to be sure it is in the current allowed channel range. If False the do not test.
Returns: None
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remove(index)[source]¶ Method to remove a segment from the segment list
Parameters: index : int
The location of the segment to remove
Returns: None
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