NDUncertainty

class astropy.nddata.NDUncertainty

Bases: object

This is the base class for uncertainty classes used with NDData. It is implemented as an abstract class and should never be directly instantiated.

Classes inheriting from NDData should overload the propagate_* methods, keeping the call signature the same. The propagate methods can assume that a parent_nddata attribute is present which links to the parent_nddata dataset, and take an NDData instance as the positional argument, not an NDUncertainty instance, because the NDData instance can be used to access both the data and the uncertainties (some propagations require the data values).

Attributes Summary

parent_nddata
supports_correlated
uncertainty_type

Methods Summary

propagate_add(other_nddata, result_data)	Propagate uncertainties for addition.
propagate_divide(other_nddata, result_data)	Propagate uncertainties for division.
propagate_multiply(other_nddata, result_data)	Propagate uncertainties for multiplication.
propagate_subtract(other_nddata, result_data)	Propagate uncertainties for subtraction.

Attributes Documentation

parent_nddata

supports_correlated = False

uncertainty_type

Methods Documentation

propagate_add(other_nddata, result_data)

Propagate uncertainties for addition.

Parameters:

other_nddata : NDData instance

The data for the second other_nddata in a + b

result_data : ndarray instance

The data array that is the result of the addition

Returns:

result_uncertainty : NDUncertainty instance

The resulting uncertainty

Raises:

IncompatibleUncertaintiesException

Raised if the method does not know how to add the uncertainties

propagate_divide(other_nddata, result_data)

Propagate uncertainties for division.

Parameters:

other_nddata : NDData instance

The data for the second other_nddata in a + b

result_data : ndarray instance

The data array that is the result of the addition

Returns:

result_uncertainty : NDUncertainty instance

The resulting uncertainty

propagate_multiply(other_nddata, result_data)

Propagate uncertainties for multiplication.

Parameters:

other_nddata : NDData instance

The data for the second other_nddata in a + b

result_data : ndarray instance

The data array that is the result of the addition

Returns:

result_uncertainty : NDUncertainty instance

The resulting uncertainty

propagate_subtract(other_nddata, result_data)

Propagate uncertainties for subtraction.

Parameters:

other_nddata : NDData instance

The data for the second other_nddata in a + b

result_data : ndarray instance

The data array that is the result of the addition

Returns:

result_uncertainty : NDUncertainty instance

The resulting uncertainty

Raises:

IncompatibleUncertaintiesException

Raised if the method does not know how to add the uncertainties