matlab equivalent of dot star in python

Question

I am working on a matlab conversion code. what is equivalent of .* in matlab with python?

len = sum(sqrt(sum(v.*v)))/N;

where v is numpy array :

v =  [array([-35289.38919481, -30575.56015338, -21456.41798462, ...,
    19796.17331542,  11216.34277023,   6977.87432284])]
N = 18225

In such cases, how will I convert code to python?

Answer 1

For numpy arrays, just using * will do the element-wise multiplication as in Matlab's .* http://wiki.scipy.org/NumPy_for_Matlab_Users

you can use,

len = numpy.sum(numpy.sqrt(numpy.sum(v[0] * v[0], axis=0))) / N 

Note: If you want to use matrices instead of arrays in numpy, you have to use the multiply method.

Answer 2

v_squared_sum = v.dot(v.transpose()) 
len_ = np.sum(np.sqrt(v_squared_sum)) / N

Answer 3

import numpy as np

v = np.array([1,2,3])
N = 3
len_ = np.sqrt(np.dot(v, v)) / N
print(len_)

Result:

1.24721912892

Do not use len as a variable name, because this shadows the built-in length function len() .