larray.Array.growth_rate¶

Array.growth_rate(self, axis=-1, d=1, label='upper')[source]¶

Calculates the growth along a given axis.

Roughly equivalent to a.diff(axis, d, label) / a[axis.i[:-d]]

Parameters:

axis : int, str, Group or Axis, optional: Axis or group along which the difference is taken. Defaults to the last axis.
d : int, optional: Periods to shift for forming difference. Defaults to 1.
label : {‘lower’, ‘upper’}, optional: The new labels in axis will have the labels of either the array being subtracted (‘lower’) or the array it is subtracted from (‘upper’). Defaults to ‘upper’.

Returns:

Array

Examples

>>> data = [[2, 4, 5, 4, 6], [4, 6, 3, 6, 9]]
>>> a = Array(data, "sex=M,F; year=2016..2020")
>>> a
sex\year  2016  2017  2018  2019  2020
       M     2     4     5     4     6
       F     4     6     3     6     9
>>> a.growth_rate()
sex\year  2017  2018  2019  2020
       M   1.0  0.25  -0.2   0.5
       F   0.5  -0.5   1.0   0.5
>>> a.growth_rate(label='lower')
sex\year  2016  2017  2018  2019
       M   1.0  0.25  -0.2   0.5
       F   0.5  -0.5   1.0   0.5
>>> a.growth_rate(d=2)
sex\year   2018  2019  2020
       M    1.5   0.0   0.2
       F  -0.25   0.0   2.0
>>> a.growth_rate('sex')
sex\year  2016  2017  2018  2019  2020
       F   1.0   0.5  -0.4   0.5   0.5
>>> a.growth_rate(a.year[2017:])
sex\year  2018  2019  2020
       M  0.25  -0.2   0.5
       F  -0.5   1.0   0.5