"""
This module contains some utility functions for math operations.
"""
import numpy as np

def get_mean(values:list):
    """
    Get the mean of the values.
    """
    return np.mean(values)


def get_x_y_mean(discrete_values:list):
    """
    Get the mean of the x and y coordinates in the discrete range.

    :param x: x coordinates
    :param y: y coordinates
    :return: mean of x and y coordinates in the discrete range
    """
    x = [vertex[0] for vertex in discrete_values]
    y = [vertex[1] for vertex in discrete_values]
    z = [vertex[2] for vertex in discrete_values]
    return get_mean(x), get_mean(y), get_mean(z)

def get_radius_from_x_y(xi:float, yi:float, x_mean:float, y_mean:float):
    """
    Get the radius from the x and y coordinates.

    :param xi: x coordinate
    :param yi: y coordinate
    :param x_mean: mean of x coordinates in the discrete range
    :param y_mean: mean of y coordinates in the discrete range
    :return: radius for this point
    """
    return np.sqrt((xi - x_mean) ** 2 + (yi - y_mean) ** 2)


def get_teta_from_x_y(xi:float, yi:float, x_mean:float, y_mean:float):
    """
    Get the teta from the x and y coordinates.

    :param xi: x coordinate
    :param yi: y coordinate
    :param x_mean: mean of x coordinates in the discrete range
    :param y_mean: mean of y coordinates in the discrete range
    :return: teta for this point
    """
    return np.arctan2((xi - x_mean)/(yi - y_mean))