SK Polarimeter

This class (polarization.py) is the model to connect to the SK Polarization analyzer from SK.

The model is similar to the controller, but it adds specific functionalities such as units with Pint and error descriptions

copyright:by Hyperion Authors, see AUTHORS for more details.
license:BSD, see LICENSE for more details.
class hyperion.instrument.polarization.polarimeter.Polarimeter(settings)

This class is the model for the SK polarization.

change_wavelength(w)

Change the current wavelegnth to w

Parameters:w (pint quantity (distance)) – wavelength
Returns:current wavelength
Return type:pint quantity (distance)
create_header(errors=False, extra_name=None, extra_unit=None, extra_description=None)

creates the header to save the data

Parameters:
  • extra_name (str) – if a first column has to be added, this is the name
  • extra_unit (str) – if a first column has to be added, this is the unit
  • extra_description (str) – if a first column has to be added, this is the description
Returns:

header with the information of the data saved
Return type:

string
finalize()

Finishes the connection to the SK polarization

get_average_data(N)

Takes N data points and gives back the average and the error (std)

Returns:av, array with dim 13 containing the average of the N measurements for each property in DATA_TYPES, and the std
Return type:numpy array
Returns:st, array with dim 13 containing the std of the N measurements for each property in DATA_TYPES, and the std
Return type:numpy array
Example:
>>> av, st = get_average_data(10)
>>> print('Values: {} +/- {}'.format(av, st))
Values
get_data()

This methods gets the a single measurement point from the device. It reads all the types of data available, listed in DATA_TYPES.

Returns:a list with the data
Return type:list
get_information()

gets the information from the device: number of polarizers and id.

get_multiple_data(N)

This is to get a stream of data directly from the device.

Parameters:N (int) – number of data points needed
Returns:a np array
get_wavelength()

asks the device the current wavelength.

Returns:current wavelength
Return type:pint quantity
initialize(wavelength=None)

This is to initialize the model by calling the initizialize function in the controller. It adds units for the wavelength

Parameters:wavelength (pint quantity) – the working wavelength
save_as_netCDF4(filename, data)

Saves the data from the polarimeter measurement into a netCDF4 file.

save_data(data, extra=[None, None, None, None], file_path='polarimeter_test.txt')

saves the data. It assumes that the data comes from the SK so it is a matrix of 13 rows and an arbitrary number of columns.

Parameters:
  • data (numpy array) – array of (N,13)
  • extra – list containing the extra vector to save (1xN), the name of the extra data and

the unit. For example: [np.array([1,2,3]),’time’,’second’,’elapsed time’]. :type extra: list

start_measurement()

This method starts the measurement for the polarization analyzer.

stop_measurement()

This method stops the measurement for the polarization analyzer.