This function performs the exponential map at (0, 0, 1) on the unit sphere.
Usage
Expmap(vec)
Arguments
vec
an element of two-dimensional Euclidean space.
Value
three-dimensional vector.
Details
This function performs exponential map at (0, 0, 1) on the unit sphere.
vec is an element of the tangent plane of the unit sphere at (0, 0, 1), and the result is an element of the unit sphere in three-dimensional Euclidean space.
References
Fletcher, P. T., Lu, C., Pizer, S. M. and Joshi, S. (2004). Principal geodesic analysis for the study of nonlinear statistics of shape. IEEE Transactions on Medical Imaging, 23, 995-1005.