pycrtools.io.interfaces

IOInterface()

Base class for data IO.

class pycrtools.io.interfaces.IOInterface

Base class for data IO.

All functions or methods that use IO should expect to interface with objects of this type and all classes that implement IO should derive from this base class and overload it’s functions.

getFFTData(data, block)

Writes FFT data for selected antennas to data array.

Required Arguments:

Parameter	Description
data	data array to write FFT data to.
block	index of block to return data from.

Output: a two dimensional array containing the FFT data of the specified block for each of the selected antennae and for the selected frequencies. So that if a is the returned array a[i] is an array of length (number of frequencies) of antenna i.

getFrequencies()

Returns the frequencies that are applicable to the FFT data

Output: This method returns a FloatVector with the selected frequencies in Hz.

getITRFAntennaPositions()

Returns antenna positions for selected antennas, or all antennas if no selection was applied.

Output: a two dimensional array containing the ITRF position of each antenna in meters in local coordinates from a predefined center. So that if a is the returned array a[i] is an array of length 3 with positions (x,y,z) of antenna i.

getReferencePosition()

Returns reference position used for antenna position coordinate system.

Output: a FloatVector with (lon,lat,height) in (rad,rad,m) of the WGS84 position of the center used for the antenna position coordinate system.

getRelativeAntennaPositions()

Returns relative antenna positions for selected antennas, or all antennas if no selection was applied.

Output: a two dimensional array containing the Cartesian position of each antenna in meters in local coordinates from a predefined center. So that if a is the returned array a[i] is an array of length 3 with positions (x,y,z) of antenna i.

getTimeseriesData(data, block)

Returns timeseries data for selected antennas.

Required Arguments:

Parameter	Description
data	data array to write timeseries data to.
block	index of block to return data from.

Output: a two dimensional array containing the timeseries data of the specified block for each of the selected antennae. So that if a is the returned array a[i] is an array of length blocksize of antenna i.

read(key, data, *args, **kwargs)

Generic read function supporting keyword arguments.

Required Arguments:

Parameter	Description
key	Data type to read.
data	array to write data to.

setAntennaSelection(selection)

Sets the antenna selection used in subsequent calls to getAntennaPositions, getFFTData, getTimeseriesData.

Required Arguments:

Parameter	Description
selection	Either Python list with index of the antenna as known to self (integers (e.g. [1, 5, 6])) Or list of IDs to specify a LOFAR dipole (e.g. ['142000005', '3001008'])

Output: This method does not return anything.

Raises: It raises a ValueError if antenna selection cannot be set to requested value (e.g. specified antenna not in file).

setFrequencyRange(fmin, fmax)

Sets the frequency selection used in subsequent calls to getFFTData. The selection set is all frequencies available for the set blocksize in the range [fmin,fmax].

Required Arguments:

Parameter	Description
fmin	minimum frequency in Hz
fmax	maximum frequency in Hz

Output: This method does not return anything.

Raises: It raises a ValueError if frequency selection cannot be set to requested values (e.g. all frequencies out of range)

setFrequencyRangeByIndex(nfmin, nfmax)

Sets the frequency selection used in subsequent calls to getFFTData. If frequencies is the array of frequencies available for the selected blocksize, then subsequent calls to getFFTData will return data corresponding to frequencies[nfmin:nfmax].

Required Arguments:

Parameter	Description
nfmin	minimum frequency as index into frequency array
nfmax	maximum frequency as index into frequency array

Output: This method does not return anything.

Raises: It raises an IndexError if frequency selection cannot be set to requested values (e.g. index out of range)

setFrequencySelection(frequencies)

Sets the frequency selection used in subsequent calls to getFFTData.

Required Arguments:

Parameter	Description
frequencies	FloatVector of frequencies in Hz

Output: This method does not return anything.

Raises: It raises a ValueError if frequency selection cannot be set to requested values (e.g. specified frequency is not available for this blocksize.)