verde.maxabs#

verde.maxabs(*args, nan=True, percentile=100)[source]#

Calculate the maximum absolute value of the given array(s).

Use this to set the limits of your colorbars and center them on zero.

Parameters:

args: One or more arrays. If more than one are given, a single maximum will be calculated across all arrays.
nanbool, optional: If True, will use the nan version of numpy functions to ignore NaNs.
percentilefloat, optional: Instead of return the maximum absolute value, return a given percentile of the absolute values. Must be between 0 and 100. A value of 100 (default) will give the maximum absolute value, while a value of 50 will give the median of the absolute values.

Returns:

maxabsfloat: The maximum (or percentile) absolute value across all arrays.

Examples

>>> result = maxabs((1, -10, 25, 2, 3))
>>> float(result)
25.0
>>> result = maxabs(
...     (1, -10.5, 25, 2), (0.1, 100, -500), (-200, -300, -0.1, -499)
... )
>>> float(result)
500.0

If the array contains NaNs, we’ll use the nan version of of the numpy functions by default. You can turn this off through the nan argument.

>>> import numpy as np
>>> result = maxabs((1, -10, 25, 2, 3, np.nan))
>>> float(result)
25.0
>>> result = maxabs((1, -10, 25, 2, 3, np.nan), nan=False)
>>> float(result)
nan

If a more robust statistic is desired, you can use percentile to get the value at a given percentile instead of the maximum.

>>> result = maxabs((1, -10, 25, 2, 3), percentile=95)
>>> float(result)
21.99
>>> result = maxabs((1, -10, 25, 2, 3), percentile=100)
>>> float(result)
25.0