feat(matrices): add logdet(::Hilbert)

TypedMatrices · Jan 20, 2025 · c17e3b8 · c17e3b8
1 parent af59f14
commit c17e3b8
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Showing 2 changed files with 6 additions and 1 deletion.
diff --git a/src/matrices/hilbert.jl b/src/matrices/hilbert.jl
@@ -52,6 +52,11 @@ LinearAlgebra.issymmetric(A::Hilbert) = A.m == A.n
     return T(one(T) / (i + j - 1))
 end
 
+logc(x) = sum([sum(log.(1:i)) for i = 2:(x-1)])
+function LinearAlgebra.logdet(A::Hilbert)
+    LinearAlgebra.checksquare(A)
+    return (4 * logc(A.n) - logc(2 * A.n))
+end
 LinearAlgebra.det(A::Hilbert) = inv(det(inv(A)))
 
 function inv(A::Hilbert{T}) where {T}

diff --git a/test/runtests.jl b/test/runtests.jl
@@ -33,7 +33,7 @@ function test_linear_algebra_functions(A::AbstractMatrix)
         @try_catch results[func] = func(A) == func(matrix)
     end
 
-    computation_functions = [adjoint, transpose, det, eigvals]
+    computation_functions = [adjoint, transpose, det, logdet, eigvals]
     if determinant != 0
         append!(computation_functions, [inv])
     end