Transports a tangent vector from one tangent space to another.
Usage
spd.transport(x, from, to = NULL, method = "gl", nsteps = NA)
Arguments
- x
A tangent vector (a symmetric matrix)
- from
The SPD matrix to whose tangent space x belongs
- to
The SPD matrix to whose tangent space to move x
- method
See details
- nsteps
For parallel transport, the number of steps along the geodesic
connecting from and to
Value
A symmetric matrix -- a tangent vector at to.
Details
Allowable method are
"pt": Parallel transport using the Schild's ladder algorithm
"gl": Transport from A to B using the GL(n) action \(A -> GAG'\), where
\(G = B^{1/2}A^{-1/2}\)
