Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Fix issymmetric for matrices with empty columns #606

Open
wants to merge 1 commit into
base: main
Choose a base branch
from
+29 −2
Open

Fix issymmetric for matrices with empty columns #606

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
10 changes: 8 additions & 2 deletions src/sparsematrix.jl
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -4074,9 +4074,9 @@ function _blockdiag(::Type{Tv}, ::Type{Ti}, X::AbstractSparseMatrixCSC...) where
end

## Structure query functions
issymmetric(A::AbstractSparseMatrixCSC) = is_hermsym(A, identity)
issymmetric(A::AbstractSparseMatrixCSC) = is_hermsym(A, transpose)

ishermitian(A::AbstractSparseMatrixCSC) = is_hermsym(A, conj)
ishermitian(A::AbstractSparseMatrixCSC) = is_hermsym(A, adjoint)

function is_hermsym(A::AbstractSparseMatrixCSC, check::Function)
m, n = size(A)
Expand Down Expand Up @@ -4112,6 +4112,12 @@ function is_hermsym(A::AbstractSparseMatrixCSC, check::Function)
return false
end
else
# if nzrange(A, row) is empty, then A[:, row] is all zeros.
# Specifically, A[col, row] is zero.
# However, we know at this point that A[row, col] is not zero
# This means that the matrix is not symmetric
isempty(nzrange(A, row)) && return false

offset = tracker[row]

# If the matrix is unsymmetric, there might not exist
Expand Down
21 changes: 21 additions & 0 deletions test/linalg.jl
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -425,6 +425,27 @@ end
@test issymmetric(sparse([1 0; 1 0])) == false
@test issymmetric(sparse([0 1; 1 0])) == true
@test issymmetric(sparse([1 1; 1 0])) == true

# test some non-trivial cases
local S
@testset "random matrices" begin
for sparsity in (0.1, 0.01, 0.0)
S = sparse(Symmetric(sprand(20, 20, sparsity)))
@test issymmetric(S)
@test ishermitian(S)
S = sparse(Symmetric(sprand(ComplexF64, 20, 20, sparsity)))
@test issymmetric(S)
@test !ishermitian(S) || isreal(S)
S = sparse(Hermitian(sprand(ComplexF64, 20, 20, sparsity)))
@test ishermitian(S)
@test !issymmetric(S) || isreal(S)
end
end

@testset "issue #605" begin
S = sparse([2, 3, 1], [1, 1, 3], [1, 1, 1], 3, 3)
@test !issymmetric(S)
end
end

@testset "rotations" begin
Expand Down
Loading