# -*- coding: utf-8 -*-
"""implement a polynomial basis function."""

import numpy as np


def build_poly(x, degree):
    """polynomial basis functions for input data x, for j=0 up to j=degree.

    Args:
        x: numpy array of shape (N,), N is the number of samples.
        degree: integer.

    Returns:
        poly: numpy array of shape (N,d+1)

    >>> build_poly(np.array([0.0, 1.5]), 2)
    array([[1.  , 0.  , 0.  ],
           [1.  , 1.5 , 2.25]])
    """
    ### SOLUTION
    poly = np.ones((len(x), 1))
    for deg in range(1, degree + 1):
        poly = np.c_[poly, np.power(x, deg)]
    return poly
    ### TEMPLATE
    # # ***************************************************
    # # COPY YOUR CODE FROM EX03 HERE
    # # polynomial basis function: TODO
    # # this function should return the matrix formed
    # # by applying the polynomial basis to the input data
    # # ***************************************************
    # raise NotImplementedError
    ### END SOLUTION