packages/vaex-core/vaex/dataframe.py
def add_virtual_columns_cartesian_velocities_to_polar(self, x="x", y="y", vx="vx", radius_polar=None, vy="vy", vr_out="vr_polar", vazimuth_out="vphi_polar",
                                                          propagate_uncertainties=False,):
        """Convert cartesian to polar velocities.

        :param x:
        :param y:
        :param vx:
        :param radius_polar: Optional expression for the radius, may lead to a better performance when given.
        :param vy:
        :param vr_out:
        :param vazimuth_out:
        :param propagate_uncertainties: {propagate_uncertainties}
        :return:
        """
        x = self._expr(x)
        y = self._expr(y)
        vx = self._expr(vx)
        vy = self._expr(vy)
        if radius_polar is None:
            radius_polar = np.sqrt(x**2 + y**2)
        radius_polar = self._expr(radius_polar)
        self[vr_out]       = (x*vx + y*vy) / radius_polar
        self[vazimuth_out] = (x*vy - y*vx) / radius_polar
        if propagate_uncertainties:
            self.propagate_uncertainties([self[vr_out], self[vazimuth_out]])
def add_virtual_columns_cartesian_velocities_to_polar(self, x="x", y="y", vx="vx", radius_polar=None, vy="vy", vr_out="vr_polar", vazimuth_out="vphi_polar",
                                                          propagate_uncertainties=False,):
        """Convert cartesian to polar velocities.

        :param x:
        :param y:
        :param vx:
        :param radius_polar: Optional expression for the radius, may lead to a better performance when given.
        :param vy:
        :param vr_out:
        :param vazimuth_out:
        :param propagate_uncertainties: {propagate_uncertainties}
        :return:
        """
        x = self._expr(x)
        y = self._expr(y)
        vx = self._expr(vx)
        vy = self._expr(vy)
        if radius_polar is None:
            radius_polar = np.sqrt(x**2 + y**2)
        radius_polar = self._expr(radius_polar)
        self[vr_out]       = (x*vx + y*vy) / radius_polar
        self[vazimuth_out] = (x*vy - y*vx) / radius_polar
        if propagate_uncertainties:
            self.propagate_uncertainties([self[vr_out], self[vazimuth_out]])
Convert cartesian to polar velocities.

        :param x:
        :param y:
        :param vx:
        :param radius_polar: Optional expression for the radius, may lead to a better performance when given.
        :param vy:
        :param vr_out:
        :param vazimuth_out:
        :param propagate_uncertainties: {propagate_uncertainties}
        :return: