fix compose on semidirect product group

JuliaManifolds · May 20, 2023 · e6702d6 · e6702d6
1 parent 5d705a2
commit e6702d6
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Showing 2 changed files with 8 additions and 1 deletion.
diff --git a/src/groups/semidirect_product_group.jl b/src/groups/semidirect_product_group.jl
@@ -123,13 +123,15 @@ function _compose!(G::SemidirectProductGroup, x, p, q)
     M = base_manifold(G)
     N, H = M.manifolds
     A = G.op.action
+    x_tmp = allocate(x)
     np, hp = submanifold_components(G, p)
     nq, hq = submanifold_components(G, q)
-    nx, hx = submanifold_components(G, x)
+    nx, hx = submanifold_components(G, x_tmp)
     compose!(H, hx, hp, hq)
     nxtmp = apply(A, hp, nq)
     compose!(N, nx, np, nxtmp)
     @inbounds _padpoint!(G, x)
+    copyto!(x, x_tmp)
     return x
 end
 

diff --git a/test/groups/semidirect_product_group.jl b/test/groups/semidirect_product_group.jl
@@ -43,6 +43,11 @@ include("group_utils.jl")
     @test compose(G, pts[1], e) == pts[1]
     @test compose(G, e, e) === e
 
+    # test in-place composition
+    o1 = copy(pts[1])
+    compose!(G, o1, o1, pts[2])
+    @test isapprox(G, o1, compose(G, pts[1], pts[2]))
+
     eA = identity_element(G)
     @test isapprox(G, eA, e)
     @test isapprox(G, e, eA)