scikit-learn Cookbook - Second Edition

Initializing NumPy arrays and dtypes

There are several ways to initialize NumPy arrays besides np.arange:

14. Initialize an array of zeros with np.zeros. The np.zeros((5,2)) command creates a 5 x 2 array of zeros:

np.zeros((5,2))array([[ 0.,  0.],       [ 0.,  0.],       [ 0.,  0.],       [ 0.,  0.],       [ 0.,  0.]])

15. Initialize an array of ones using np.ones. Introduce a dtype argument, set to np.int, to ensure that the ones are of NumPy integer type. Note that scikit-learn expects np.float arguments in arrays. The dtype refers to the type of every element in a NumPy array. It remains the same throughout the array. Every single element of the array below has a np.int integer type.

np.ones((5,2), dtype = np.int)array([[1, 1],       [1, 1],       [1, 1],       [1, 1],       [1, 1]])

16. Use