Is the math of calc_vector function right?

[FabricioMatos]

https://github.com/dieegom/brumadinho_location/blob/a252f2de7727c90026db38c4a25511abfb067bed/backend/utils.py#L29

I don't know what is the expected result of this function, but it's returning: (2 * self.lat - barragem.lat), (2 * self.lng - barragem.lng) as we can see:

    def calc_vector(self):
        v_pos_x, v_pos_y = (self.lat - barragem[0], self.lng - barragem[1])
        d = np.sqrt((v_pos_x ** 2 + v_pos_y ** 2))
        print(v_pos_x, v_pos_y, d)
        xf = self.lat + v_pos_x
        yf = self.lng + v_pos_y
        return xf, yf

I couldn't follow the reasoning here.

[RodriguesCSI]

As long as I understood of the code, it first calculate the Euclidean distance and then it does a translation from the self location to a new one. In the cartesian plane result with a line with 3 points, where the self position encounters in the middle of the others 2. The function returns the translated position.