``c_geodetic_lat_from_reduced_lat``
===================================

.. c:function:: double Ellipsoid.c_geodetic_lat_from_reduced_lat(double reduced_lat)

Compute the geodetic latitude :math:`\phi` from a reduced (parametric) latitude :math:`\beta`.

.. math::
    \phi = \arctan\!\Bigl(\frac{\tan\beta}{1 - f}\Bigr)


All angles are in radians (SI).

:param reduced_lat: 
    Reduced (parametric) latitude :math:`\beta` in radians.

:returns: 
    Geodetic latitude :math:`\phi` in radians.

:rtype: 
    float


.. seealso::
    :c:func:`c_reduced_lat_from_geodetic_lat <Ellipsoid.c_reduced_lat_from_geodetic_lat>`
        Forward transform (β from φ).

    :meth:`geodetic_lat_from_reduced_lat <Ellipsoid.geodetic_lat_from_reduced_lat>` 
        Vectorized Python wrapper.

.. note::
    Releases the GIL and uses a low-level C implementation for speed.