get_wide_all_external_mask#

caf.toolkit.pandas_utils.get_wide_all_external_mask(df, select)[source]#

Generate an external only mask for a wide matrix.

This is a common operation in wide travel demand matrices. When a matrix contains both “internal” and “external” demand, this function can be used to generate a mask that selects the “external to external”, “external_to_internal”, and “internal to external” area.

To extract values from the given df perform df * mask.

Parameters:

  • df (DataFrame) – The Pandas DataFrame to generate the mask for.

  • select (list[Any]) – A list of index/column identifiers that should be selected.

Returns:

A mask of True and False values. Will be the same shape as df.

Return type:

mask

See also

get_wide_mask(), get_wide_internal_only_mask()

Examples

External zones in travel demand matrices tend to be the last in the matrix

>>> df = pd.DataFrame(np.full((4, 4), 5))
>>> df
   0  1  2  3
0  5  5  5  5
1  5  5  5  5
2  5  5  5  5
3  5  5  5  5

>>> mask = get_wide_all_external_mask(df,select=[2, 3])
>>> mask
array([[False, False,  True,  True],
       [False, False,  True,  True],
       [ True,  True,  True,  True],
       [ True,  True,  True,  True]])

Values can be extracted using multiplication

>>> df * mask
   0  1  2  3
0  0  0  5  5
1  0  0  5  5
2  5  5  5  5
3  5  5  5  5