Skip to content

fix infinite loop in cond #682

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

Open
araujoms wants to merge 1 commit into
base: main
Choose a base branch
from
+12 −8
Open

fix infinite loop in cond #682

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
2 changes: 1 addition & 1 deletion src/linalg.jl
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -1742,7 +1742,7 @@ function opnormestinv(A::AbstractSparseMatrixCSC{T}, t::Integer = min(2,maximum(
repeated = true
end
end
if !repeated
if !repeated && n > 2
saux2 = S[1:n,j]' * S_old[1:n,1:t]
if _any_abs_eq(saux2,n)
repeated = true
Expand Down
18 changes: 11 additions & 7 deletions test/linalg_solvers.jl
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -129,20 +129,24 @@ end

@testset "sparse matrix cond" begin
local A = sparse(reshape([1.0], 1, 1))
Ac = sprandn(20, 20,.5) + im*sprandn(20, 20,.5)
Ar = sprandn(20, 20,.5) + eps()*I
@test cond(A, 1) == 1.0
# For a discussion of the tolerance, see #14778
@test 0.99 <= cond(Ar, 1) \ opnorm(Ar, 1) * opnorm(inv(Array(Ar)), 1) < 3
@test 0.99 <= cond(Ac, 1) \ opnorm(Ac, 1) * opnorm(inv(Array(Ac)), 1) < 3
@test 0.99 <= cond(Ar, Inf) \ opnorm(Ar, Inf) * opnorm(inv(Array(Ar)), Inf) < 3
@test 0.99 <= cond(Ac, Inf) \ opnorm(Ac, Inf) * opnorm(inv(Array(Ac)), Inf) < 3
@test_throws ArgumentError cond(A,2)
@test_throws ArgumentError cond(A,3)
Arect = spzeros(10, 6)
@test_throws DimensionMismatch cond(Arect, 1)
@test_throws ArgumentError cond(Arect,2)
@test_throws DimensionMismatch cond(Arect, Inf)
Ac = sprandn(20, 20,.5) + im*sprandn(20, 20,.5)
Ar = sprandn(20, 20,.5) + eps()*I
# For a discussion of the tolerance, see #14778
@test 0.99 <= cond(Ar, 1) \ opnorm(Ar, 1) * opnorm(inv(Array(Ar)), 1) < 3
@test 0.99 <= cond(Ac, 1) \ opnorm(Ac, 1) * opnorm(inv(Array(Ac)), 1) < 3
@test 0.99 <= cond(Ar, Inf) \ opnorm(Ar, Inf) * opnorm(inv(Array(Ar)), Inf) < 3
@test 0.99 <= cond(Ac, Inf) \ opnorm(Ac, Inf) * opnorm(inv(Array(Ac)), Inf) < 3
#issue 680
A22 = sparse(randn(2,2))
@test 0.99 ≤ cond(Array(A22), 1) / cond(A22, 1) < 3
@test 0.99 ≤ cond(Array(A22), Inf) / cond(A22, Inf) < 3
end

@testset "sparse matrix opnormestinv" begin
Expand Down
Loading