PackedSelection

class coffea.analysis_tools.PackedSelection(dtype='uint32')[source]

Bases: object

Store several boolean arrays in a compact manner

This class can store several boolean arrays in a memory-efficient mannner and evaluate arbitrary combinations of boolean requirements in an CPU-efficient way. Supported inputs are 1D numpy or awkward arrays.

Parameters:: dtype (numpy.dtype or str) – internal bitwidth of the packed array, which governs the maximum number of selections storable in this object. The default value is uint32, which allows up to 32 booleans to be stored, but if a smaller or larger number of selections needs to be stored, one can choose uint16 or uint64 instead.

Attributes Summary

`maxitems`
`names`	Current list of mask names available

Methods Summary

`add`(name, selection[, fill_value])	Add a new boolean array
`all`(*names)	Shorthand for `require`, where all the values are True
`any`(*names)	Return a mask vector corresponding to an inclusive OR of requirements
`require`(**names)	Return a mask vector corresponding to specific requirements

Attributes Documentation

maxitems

names: Current list of mask names available

Methods Documentation

add(name, selection, fill_value=False)[source]

Add a new boolean array

Parameters:

name (str) – name of the selection
selection (numpy.ndarray or awkward.Array) – a flat array of type bool or ?bool. If this is not the first selection added, it must also have the same shape as previously added selections. If the array is option-type, null entries will be filled with fill_value.
fill_value (bool, optional) – All masked entries will be filled as specified (default: False)

all(*names)[source]: Shorthand for require, where all the values are True

any(*names)[source]

Return a mask vector corresponding to an inclusive OR of requirements

Parameters:: *names (args) – The named selections to allow

Examples

If

>>> selection.names
['cut1', 'cut2', 'cut3']

then

>>> selection.any("cut1", "cut2")
array([True, False, True, ...])

returns a boolean array where an entry is True if the corresponding entries cut1 == True or cut2 == False, and cut3 arbitrary.

require(**names)[source]

Return a mask vector corresponding to specific requirements

Specify an exact requirement on an arbitrary subset of the masks

Parameters:: **names (kwargs) – Each argument to require specific value for, in form arg=True or arg=False.

Examples

If

>>> selection.names
['cut1', 'cut2', 'cut3']

then

>>> selection.require(cut1=True, cut2=False)
array([True, False, True, ...])

returns a boolean array where an entry is True if the corresponding entries cut1 == True, cut2 == False, and cut3 arbitrary.