spd.transport: Transport a tangent vector
In areshenk/spdm: Functions for working with symmetric positive-definite matrices

spd.transport

R Documentation

Transport a tangent vector

Transports a tangent vector from one tangent space to another.

spd.transport(x, from, to = NULL, method = "gl", nsteps = NA)

`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

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}