Fix retarction with t on power manifold (#175)

* define t-specialisations on retractions for power manifolds.
* write a news entry.
* Simplify code, add tests for t-retractions on power manifolds.
* runs formatter.
* Bump version.

Author: kellertuer

NEWS.md

@@ -5,6 +5,12 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
+## [0.15.4] 25/11/2023
+
+### Fixed
+
+* Fixed a bug reported in [Manopt#330](https://github.com/JuliaManifolds/Manopt.jl/issues/330).
+
 ## [0.15.3] 17/11/2023
 
 ### Fixed

Project.toml

@@ -1,7 +1,7 @@
 name = "ManifoldsBase"
 uuid = "3362f125-f0bb-47a3-aa74-596ffd7ef2fb"
 authors = ["Seth Axen <[email protected]>", "Mateusz Baran <[email protected]>", "Ronny Bergmann <[email protected]>", "Antoine Levitt <[email protected]>"]
-version = "0.15.3"
+version = "0.15.4"
 
 [deps]
 LinearAlgebra = "37e2e46d-f89d-539d-b4ee-838fcccc9c8e"

src/PowerManifold.jl

@@ -1291,6 +1291,43 @@ function retract!(
     return q
 end
 
+function retract!(
+    M::AbstractPowerManifold,
+    q,
+    p,
+    X,
+    t::Number,
+    m::AbstractRetractionMethod = default_retraction_method(M, typeof(p)),
+)
+    rep_size = representation_size(M.manifold)
+    for i in get_iterator(M)
+        retract!(
+            M.manifold,
+            _write(M, rep_size, q, i),
+            _read(M, rep_size, p, i),
+            _read(M, rep_size, X, i),
+            t,
+            m,
+        )
+    end
+    return q
+end
+function retract!(
+    M::PowerManifoldNestedReplacing,
+    q,
+    p,
+    X,
+    t::Number,
+    m::AbstractRetractionMethod = default_retraction_method(M, typeof(p)),
+)
+    rep_size = representation_size(M.manifold)
+    for i in get_iterator(M)
+        q[i...] =
+            retract(M.manifold, _read(M, rep_size, p, i), _read(M, rep_size, X, i), t, m)
+    end
+    return q
+end
+
 @doc raw"""
     riemann_tensor(M::AbstractPowerManifold, p, X, Y, Z)
 

test/power.jl

@@ -141,6 +141,10 @@ struct TestArrayRepresentation <: AbstractPowerRepresentation end
                     @test retract(N, p, q, ExponentialRetraction()) == p .+ q
                     r = allocate(p)
                     @test retract!(N, r, p, q, ExponentialRetraction()) == p .+ q
+                    @test retract(N, p, q, 1.0) == p .+ q
+                    @test retract(N, p, q, 1.0, ExponentialRetraction()) == p .+ q
+                    r = allocate(p)
+                    @test retract!(N, r, p, q, 1.0, ExponentialRetraction()) == p .+ q
                     @test r == p .+ q
                     @test inverse_retract(N, p, r) == q
                     @test inverse_retract(N, p, r, LogarithmicInverseRetraction()) == q