add method log_lbfgs - Riemannian logarithm using expm_frechet -

docs/src/manifolds/stiefel.md

@@ -54,6 +54,14 @@ Public = true
 Private = false
 ```
 
+```@autodocs
+Modules = [Manifolds]
+Pages = ["manifolds/StiefelFrechet.jl"]
+Order = [:type, :function]
+Public = true
+Private = false
+```
+
 ## Internal types and functions
 
 ```@autodocs

docs/src/misc/internals.md

@@ -7,8 +7,10 @@ This page documents the internal types and methods of `Manifolds.jl`'s that migh
 ```@docs
 Manifolds.eigen_safe
 Manifolds.isnormal
+Manifolds.expm_frechet
 Manifolds.log_safe
 Manifolds.log_safe!
+Manifolds.minimize
 Manifolds.mul!_safe
 Manifolds.nzsign
 Manifolds.realify

src/Manifolds.jl

@@ -278,6 +278,8 @@ using StatsBase
 using StatsBase: AbstractWeights
 
 include("utils.jl")
+include("expm_frechet.jl")
+include("minimize_lbfgs.jl")
 
 include("product_representations.jl")
 include("differentiation/differentiation.jl")
@@ -345,6 +347,7 @@ include("manifolds/Stiefel.jl")
 include("manifolds/StiefelEuclideanMetric.jl")
 include("manifolds/StiefelCanonicalMetric.jl")
 include("manifolds/StiefelSubmersionMetric.jl")
+include("manifolds/StiefelFrechet.jl")
 include("manifolds/Sphere.jl")
 include("manifolds/SphereSymmetricMatrices.jl")
 include("manifolds/Symmetric.jl")
@@ -659,13 +662,17 @@ export ×,
     differential_canonical_project,
     differential_canonical_project!,
     distance,
+    dot_exp,
+    dot_exp!,
     dual_basis,
     einstein_tensor,
     embed,
     embed!,
     equiv,
     exp,
     exp!,
+    exp_frechet,
+    exp_frechet!,
     flat,
     flat!,
     gaussian_curvature,
@@ -702,6 +709,7 @@ export ×,
     local_metric_jacobian,
     log,
     log!,
+    log_lbfgs,
     log_local_metric_density,
     manifold_dimension,
     metric,