Add missing logabsdet(LDLt{SymTridiagonal}) method (#24085)

* Add missing logabsdet(LDLt{SymTridiagonal}) method * Fix seed for some of the sparse tests calling factorize
JuliaLang · Oct 11, 2017 · 93a38b7 · 93a38b7
1 parent cd8bda2
commit 93a38b7
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Showing 3 changed files with 35 additions and 22 deletions.
diff --git a/base/linalg/ldlt.jl b/base/linalg/ldlt.jl
@@ -121,6 +121,11 @@ function A_ldiv_B!(S::LDLt{T,M}, B::AbstractVecOrMat{T}) where {T,M<:SymTridiago
     return B
 end
 
+function logabsdet(F::LDLt{<:Any,<:SymTridiagonal})
+    it = (F.data[i,i] for i in 1:size(F, 1))
+    return sum(log∘abs, it), prod(sign, it)
+end
+
 # Conversion methods
 function convert(::Type{SymTridiagonal}, F::LDLt)
     e = copy(F.data.ev)

diff --git a/test/linalg/tridiag.jl b/test/linalg/tridiag.jl
@@ -291,6 +291,12 @@ guardsrand(123) do
                             @test isa(similar(Ts, Int), SymTridiagonal{Int})
                             @test isa(similar(Ts, Int, (3,2)), Matrix{Int})
                         end
+
+                        @test first(logabsdet(Tldlt)) ≈ first(logabsdet(Fs))
+                        @test last(logabsdet(Tldlt))  ≈ last(logabsdet(Fs))
+                        # just test that the det method exists. The numerical value of the
+                        # determinant is unreliable
+                        det(Tldlt)
                     end
                 end
             else # mat_type is Tridiagonal

diff --git a/test/sparse/sparse.jl b/test/sparse/sparse.jl
@@ -1696,28 +1696,30 @@ end
 end
 
 @testset "factorization" begin
-    local A
-    A = sparse(Diagonal(rand(5))) + sprandn(5, 5, 0.2) + im*sprandn(5, 5, 0.2)
-    A = A + A'
-    @test !Base.USE_GPL_LIBS || abs(det(factorize(Hermitian(A)))) ≈ abs(det(factorize(Array(A))))
-    A = sparse(Diagonal(rand(5))) + sprandn(5, 5, 0.2) + im*sprandn(5, 5, 0.2)
-    A = A*A'
-    @test !Base.USE_GPL_LIBS || abs(det(factorize(Hermitian(A)))) ≈ abs(det(factorize(Array(A))))
-    A = sparse(Diagonal(rand(5))) + sprandn(5, 5, 0.2)
-    A = A + A.'
-    @test !Base.USE_GPL_LIBS || abs(det(factorize(Symmetric(A)))) ≈ abs(det(factorize(Array(A))))
-    A = sparse(Diagonal(rand(5))) + sprandn(5, 5, 0.2)
-    A = A*A.'
-    @test !Base.USE_GPL_LIBS || abs(det(factorize(Symmetric(A)))) ≈ abs(det(factorize(Array(A))))
-    @test factorize(triu(A)) == triu(A)
-    @test isa(factorize(triu(A)), UpperTriangular{Float64, SparseMatrixCSC{Float64, Int}})
-    @test factorize(tril(A)) == tril(A)
-    @test isa(factorize(tril(A)), LowerTriangular{Float64, SparseMatrixCSC{Float64, Int}})
-    @test !Base.USE_GPL_LIBS || factorize(A[:, 1:4])\ones(size(A, 1)) ≈ Array(A[:, 1:4])\ones(size(A, 1))
-    @test_throws ErrorException chol(A)
-    @test_throws ErrorException lu(A)
-    @test_throws ErrorException eig(A)
-    @test_throws ErrorException inv(A)
+    guardsrand(123) do
+        local A
+        A = sparse(Diagonal(rand(5))) + sprandn(5, 5, 0.2) + im*sprandn(5, 5, 0.2)
+        A = A + A'
+        @test !Base.USE_GPL_LIBS || abs(det(factorize(Hermitian(A)))) ≈ abs(det(factorize(Array(A))))
+        A = sparse(Diagonal(rand(5))) + sprandn(5, 5, 0.2) + im*sprandn(5, 5, 0.2)
+        A = A*A'
+        @test !Base.USE_GPL_LIBS || abs(det(factorize(Hermitian(A)))) ≈ abs(det(factorize(Array(A))))
+        A = sparse(Diagonal(rand(5))) + sprandn(5, 5, 0.2)
+        A = A + A.'
+        @test !Base.USE_GPL_LIBS || abs(det(factorize(Symmetric(A)))) ≈ abs(det(factorize(Array(A))))
+        A = sparse(Diagonal(rand(5))) + sprandn(5, 5, 0.2)
+        A = A*A.'
+        @test !Base.USE_GPL_LIBS || abs(det(factorize(Symmetric(A)))) ≈ abs(det(factorize(Array(A))))
+        @test factorize(triu(A)) == triu(A)
+        @test isa(factorize(triu(A)), UpperTriangular{Float64, SparseMatrixCSC{Float64, Int}})
+        @test factorize(tril(A)) == tril(A)
+        @test isa(factorize(tril(A)), LowerTriangular{Float64, SparseMatrixCSC{Float64, Int}})
+        @test !Base.USE_GPL_LIBS || factorize(A[:, 1:4])\ones(size(A, 1)) ≈ Array(A[:, 1:4])\ones(size(A, 1))
+        @test_throws ErrorException chol(A)
+        @test_throws ErrorException lu(A)
+        @test_throws ErrorException eig(A)
+        @test_throws ErrorException inv(A)
+    end
 end
 
 @testset "issue #13792, use sparse triangular solvers for sparse triangular solves" begin