restrict the default left-invariant log and exp on groups to semidire…

…ct products for now
JuliaManifolds · Aug 8, 2024 · 89ec7e6 · 89ec7e6
1 parent 8a0a988
commit 89ec7e6
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diff --git a/NEWS.md b/NEWS.md
@@ -14,7 +14,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 * `SpecialEuclidean` group now has a different default tangent vector representation, the left-invariant one; to get the old representation pass `gvr=HybridTangentRepresentation()` to the constructor of `SpecialEuclidean`.
 * `adjoint_action` takes a direction argument; by default it is `LeftAction`.
 * `adjoint_action!` is the necessary method to implement in groups with left-invariant tangent vector representation.
-* On groups with invariant vector storage, `exp` and `log` are based on `exp_lie` and `log_lie` and thus group invariant.
+* On semidirect product groups with left-invariant vector storage, `exp` and `log` are based on `exp_lie` and `log_lie` and thus group invariant.
 * Fixed a few typos in the doc string of the SPD fixed determinant description.
 
 ### Removed

diff --git a/src/groups/group.jl b/src/groups/group.jl
@@ -1238,52 +1238,6 @@ end
 direction_and_side(::GroupExponentialRetraction{D}) where {D} = D()
 direction_and_side(::GroupLogarithmicInverseRetraction{D}) where {D} = D()
 
-function log(
-    ::TraitList{<:IsGroupManifold,<:LeftInvariantRepresentation},
-    G::AbstractDecoratorManifold,
-    p,
-    q,
-)
-    BG = base_group(G)
-    return log_lie(BG, compose(BG, inv(BG, p), q))
-end
-function log!(
-    ::TraitList{<:IsGroupManifold,<:LeftInvariantRepresentation},
-    G::AbstractDecoratorManifold,
-    X,
-    p,
-    q,
-)
-    x = allocate_result(G, inv)
-    BG = base_group(G)
-    inv!(BG, x, p)
-    compose!(BG, x, x, q)
-    log_lie!(BG, X, x)
-    return X
-end
-function exp(
-    ::TraitList{<:IsGroupManifold,<:LeftInvariantRepresentation},
-    G::AbstractDecoratorManifold,
-    p,
-    X,
-    t::Number=1,
-)
-    BG = base_group(G)
-    return compose(BG, p, exp_lie(BG, t * X))
-end
-function exp!(
-    ::TraitList{<:IsGroupManifold,<:LeftInvariantRepresentation},
-    G::AbstractDecoratorManifold,
-    q,
-    p,
-    X,
-)
-    BG = base_group(G)
-    exp_lie!(BG, q, X)
-    compose!(BG, q, p, q)
-    return q
-end
-
 @doc raw"""
     retract(
         G::AbstractDecoratorManifold,

diff --git a/src/groups/semidirect_product_group.jl b/src/groups/semidirect_product_group.jl
@@ -265,3 +265,57 @@ function submanifold_components(
 )
     return map(N -> Identity(N), M.manifolds)
 end
+
+function log(
+    ::TraitList{
+        <:IsGroupManifold{<:SemidirectProductOperation,<:LeftInvariantRepresentation},
+    },
+    G::AbstractDecoratorManifold,
+    p,
+    q,
+)
+    BG = base_group(G)
+    return log_lie(BG, compose(BG, inv(BG, p), q))
+end
+function log!(
+    ::TraitList{
+        <:IsGroupManifold{<:SemidirectProductOperation,<:LeftInvariantRepresentation},
+    },
+    G::AbstractDecoratorManifold,
+    X,
+    p,
+    q,
+)
+    x = allocate_result(G, inv)
+    BG = base_group(G)
+    inv!(BG, x, p)
+    compose!(BG, x, x, q)
+    log_lie!(BG, X, x)
+    return X
+end
+function exp(
+    ::TraitList{
+        <:IsGroupManifold{<:SemidirectProductOperation,<:LeftInvariantRepresentation},
+    },
+    G::AbstractDecoratorManifold,
+    p,
+    X,
+    t::Number=1,
+)
+    BG = base_group(G)
+    return compose(BG, p, exp_lie(BG, t * X))
+end
+function exp!(
+    ::TraitList{
+        <:IsGroupManifold{<:SemidirectProductOperation,<:LeftInvariantRepresentation},
+    },
+    G::AbstractDecoratorManifold,
+    q,
+    p,
+    X,
+)
+    BG = base_group(G)
+    exp_lie!(BG, q, X)
+    compose!(BG, q, p, q)
+    return q
+end
diff --git a/test/groups/groups_general.jl b/test/groups/groups_general.jl
@@ -90,6 +90,8 @@ using Manifolds:
         @test_throws MethodError inv!(G, p, p)
         @test_throws MethodError inv!(G, p, eg)
         @test_throws MethodError inv(G, p)
+        @test_throws MethodError inv_diff(G, p, X)
+        @test_throws MethodError inv_diff!(G, X, p, X)
 
         # no function defined to return the identity array representation
         @test_throws MethodError copyto!(G, p, eg)