segments.py

import numpy as np
from numpy.testing import assert_array_equal

def segments(x, y, bp_x, bp_y):
    """
    recibe dos arrays de 1D (x, y) y otros dos vectores (bp_x, bp_y) que  dan las coordenadas de algunos puntos  en x,y.. 
    Devuelve una tupla (X_segs, Y_segs) cada uno de 2D, donde cada fila es el 
    segmento del array original hasta el valor más a cercano a un punto en (bp_x, bp_y)
    """
    # to do
    pass 



def test_simple():
    x = np.array([1, 2, 3, 4, 5])
    y = np.array([-5, 3, 4.1, 10, 12])
    x_segs, y_segs = segments(x, y, [3], [4.1])
    assert_array_equal(x_segs, [[1, 2, 3], 
                                [4, 5]])
    assert_array_equal(y_segs, [[-5, 3, 4.1], 
                                [10, 12]])


def test_multiples_points():
    x = np.array([1, 2, 3, 4, 5, 6, 7])
    y = np.array([-5, 3, 4.1, 10, 10, 10, 10])
    x_segs, y_segs = segments(x, y, [2, 5], [3, 10])
    assert_array_equal(x_segs, [[1, 2], 
                                [3, 4, 5], 
                                [6, 7]])
    assert_array_equal(y_segs, [[-5, 3], 
                                [4.1, 10, 10],
                                [10, 10]])


def test_break_points_are_not_explicitly_in_x_y():
    x = np.linspace(-2, 2, 10)
    y = x ** 2
    x_segs, y_segs = segments(x, y, [0], [0])
    expected_x_segs = np.array([
        [-2.        , -1.55555556, -1.11111111, -0.66666667, -0.22222222],
        [0.22222222,  0.66666667,  1.11111111,  1.55555556,  2.         ]
    ])
    expected_y_segs = np.array([
        [4.        ,  2.41975309,  1.2345679 ,  0.44444444,  0.04938272],
        [0.04938272,  0.44444444,  1.2345679 ,  2.41975309,  4.        ]
    ])
    assert_array_equal(x_segs, expected_x_segs)
    assert_array_equal(y_segs, expected_y_segs)