`numpy:max`

source: /dev/numpy/build-install/usr/lib/python3.14/site-packages/numpy/_core/fromnumeric.py :3011

Signature

   def     max (    a    ,    axis    =  None   ,    out    =  None   ,    keepdims    =  <no value>   ,    initial    =  <no value>   ,    where    =  <no value>     )

Summary

Return the maximum of an array or maximum along an axis.

Parameters

a : array_like

Input data.

axis : None or int or tuple of ints, optional

Axis or axes along which to operate. By default, flattened input is used. If this is a tuple of ints, the maximum is selected over multiple axes, instead of a single axis or all the axes as before.

out : ndarray, optional

Alternative output array in which to place the result. Must be of the same shape and buffer length as the expected output. See ufuncs-output-type for more details.

keepdims : bool, optional

If this is set to True, the axes which are reduced are left in the result as dimensions with size one. With this option, the result will broadcast correctly against the input array.

If the default value is passed, then keepdims will not be passed through to the max method of sub-classes of ndarray, however any non-default value will be. If the sub-class' method does not implement keepdims any exceptions will be raised.

initial : scalar, optional

The minimum value of an output element. Must be present to allow computation on empty slice. See ~numpy.ufunc.reduce for details.

where : array_like of bool, optional

Elements to compare for the maximum. See ~numpy.ufunc.reduce for details.

Returns

max : ndarray or scalar: Maximum of a. If axis is None, the result is a scalar value. If axis is an int, the result is an array of dimension a.ndim - 1. If axis is a tuple, the result is an array of dimension a.ndim - len(axis).

Notes

NaN values are propagated, that is if at least one item is NaN, the corresponding max value will be NaN as well. To ignore NaN values (MATLAB behavior), please use nanmax.

Don't use max for element-wise comparison of 2 arrays; when a.shape[0] is 2, maximum(a[0], a[1]) is faster than max(a, axis=0).

Examples

import numpy as np
a = np.arange(4).reshape((2,2))
a

✓

np.max(a)           # Maximum of the flattened array

✗

np.max(a, axis=0)   # Maxima along the first axis
np.max(a, axis=1)   # Maxima along the second axis
np.max(a, where=[False, True], initial=-1, axis=0)
b = np.arange(5, dtype=float)
b[2] = np.nan
np.max(b)

✓

np.max(b, where=~np.isnan(b), initial=-1)
np.nanmax(b)

✗

You can use an initial value to compute the maximum of an empty slice, or to initialize it to a different value:

np.max([[-50], [10]], axis=-1, initial=0)

✓

Notice that the initial value is used as one of the elements for which the maximum is determined, unlike for the default argument Python's max function, which is only used for empty iterables.

np.max([5], initial=6)

✗

max([5], default=6)

⚠

Aliases

numpy.max