max of a column in a numpy array in python

Question

In Matlab you can do things such as

Mat1[: , end] = max( Value1 * (Mat2[:, end]-Value2 ),0)

I tried the equivalent in Python but i'm getting an error and i'm not sure why

Mat1[: , -1] = max( Value1 * (Mat2[:, -1]-Value2 ),0)

The error is below

ValueError: The truth value of an array with more than one element is ambiguous. Use a.any() or a.all()

zhangxaochen · Accepted Answer · 2014-02-16 09:31:19Z

1

You are using the python builtin method max, use np.max instead:

import numpy as np
Mat1[: , -1] = np.max( Value1 * (Mat2[:, -1]-Value2 ),0)

answered Feb 16, 2014 at 9:31

zhangxaochen

34.2k15 gold badges82 silver badges115 bronze badges

Sign up to request clarification or add additional context in comments.

2 Comments

its the little things you forget at 4 am that make all the difference thanks

I'm sure I don't represent any majority