def template_sphere (radius, dimensions):
    r"""
    Returns a spherical binary structure of a of the supplied radius that can be used as
    template input to the generalized hough transform.

    Parameters
    ----------
    radius : integer
        The circles radius in voxels.
    dimensions : integer
        The dimensionality of the circle

    Returns
    -------
    template_sphere : ndarray
        A boolean array containing a sphere.
    """
    if int(dimensions) != dimensions:
        raise TypeError('The supplied dimension parameter must be of type integer.')
    dimensions = int(dimensions)
    
    return template_ellipsoid(dimensions * [radius * 2])