Function are_collinear

maths/points_are_collinear_3d.py:96–126

Check if three points are collinear or not. 1- Create two vectors AB and AC. 2- Get the cross vector of the two vectors. 3- Calculate the length of the cross vector. 4- If the length is zero then the points are collinear, else they are not. The use of the accuracy paramete

(a: Point3d, b: Point3d, c: Point3d, accuracy: int = 10)

def are_collinear(a: Point3d, b: Point3d, c: Point3d, accuracy: int = 10) -> bool:
    """
    Check if three points are collinear or not.

    1- Create two vectors AB and AC.
    2- Get the cross vector of the two vectors.
    3- Calculate the length of the cross vector.
    4- If the length is zero then the points are collinear, else they are not.

    The use of the accuracy parameter is explained in is_zero_vector docstring.

    >>> are_collinear((4.802293498137402, 3.536233125455244, 0),
    ...               (-2.186788107953106, -9.24561398001649, 7.141509524846482),
    ...               (1.530169574640268, -2.447927606600034, 3.343487096469054))
    True
    >>> are_collinear((-6, -2, 6),
    ...               (6.200213806439997, -4.930157614926678, -4.482371908289856),
    ...               (-4.085171149525941, -2.459889509029438, 4.354787180795383))
    True
    >>> are_collinear((2.399001826862445, -2.452009976680793, 4.464656666157666),
    ...               (-3.682816335934376, 5.753788986533145, 9.490993909044244),
    ...               (1.962903518985307, 3.741415730125627, 7))
    False
    >>> are_collinear((1.875375340689544, -7.268426006071538, 7.358196269835993),
    ...               (-3.546599383667157, -4.630005261513976, 3.208784032924246),
    ...               (-2.564606140206386, 3.937845170672183, 7))
    False
    """
    ab = create_vector(a, b)
    ac = create_vector(a, c)
    return is_zero_vector(get_3d_vectors_cross(ab, ac), accuracy)