Mean Squared Error in Numpy? Mean Squared Error in Numpy? python python

Mean Squared Error in Numpy?


You can use:

mse = ((A - B)**2).mean(axis=ax)

Or

mse = (np.square(A - B)).mean(axis=ax)
  • with ax=0 the average is performed along the row, for each column, returning an array
  • with ax=1 the average is performed along the column, for each row, returning an array
  • with ax=None the average is performed element-wise along the array, returning a scalar value


This isn't part of numpy, but it will work with numpy.ndarray objects. A numpy.matrix can be converted to a numpy.ndarray and a numpy.ndarray can be converted to a numpy.matrix.

from sklearn.metrics import mean_squared_errormse = mean_squared_error(A, B)

See Scikit Learn mean_squared_error for documentation on how to control axis.


Even more numpy

np.square(np.subtract(A, B)).mean()