Remove checks in tril, triu, and diag (JuliaLang#28480)

* Stop throwing for out of bounds diagonals in tril, triu and diag
defined in LinearAlgebra

* Remove checks from tril, triu and diag in SparseArrays

stdlib/LinearAlgebra/src/dense.jl

@@ -171,17 +171,10 @@ julia> triu!(M, 1)
 function triu!(M::AbstractMatrix, k::Integer)
  @assert !has_offset_axes(M)
  m, n = size(M)
- if !(-m + 1 <= k <= n + 1)
- throw(ArgumentError(string("the requested diagonal, $k, must be at least ",
- "$(-m + 1) and at most $(n + 1) in an $m-by-$n matrix")))
- end
- idx = 1
- for j = 0:n-1
- ii = min(max(0, j+1-k), m)
- for i = (idx+ii):(idx+m-1)
- M[i] = zero(M[i])
+ for j in 1:min(n, n + k)
+ for i in max(1, j - k + 1):m
+ M[i,j] = zero(M[i,j])
  end
- idx += m
  end
  M
 end
@@ -216,17 +209,10 @@ julia> tril!(M, 2)
 function tril!(M::AbstractMatrix, k::Integer)
  @assert !has_offset_axes(M)
  m, n = size(M)
- if !(-m - 1 <= k <= n - 1)
- throw(ArgumentError(string("the requested diagonal, $k, must be at least ",
- "$(-m - 1) and at most $(n - 1) in an $m-by-$n matrix")))
- end
- idx = 1
- for j = 0:n-1
- ii = min(max(0, j-k), m)
- for i = idx:(idx+ii-1)
- M[i] = zero(M[i])
+ for j in max(1, k + 1):n
+ @inbounds for i in 1:min(j - k - 1, m)
+ M[i,j] = zero(M[i,j])
  end
- idx += m
  end
  M
 end
@@ -249,13 +235,8 @@ function fillband!(A::AbstractMatrix{T}, x, l, u) where T
  return A
 end
 
-function diagind(m::Integer, n::Integer, k::Integer=0)
- if !(-m <= k <= n)
- throw(ArgumentError(string("requested diagonal, $k, must be at least $(-m) and ",
- "at most $n in an $m-by-$n matrix")))
- end
+diagind(m::Integer, n::Integer, k::Integer=0) =
  k <= 0 ? range(1-k, step=m+1, length=min(m+k, n)) : range(k*m+1, step=m+1, length=min(m, n-k))
-end
 
 """
  diagind(M, k::Integer=0)

stdlib/LinearAlgebra/src/triangular.jl

@@ -243,10 +243,7 @@ istriu(A::Transpose) = istril(A.parent)
 
 function tril!(A::UpperTriangular, k::Integer=0)
  n = size(A,1)
- if !(-n - 1 <= k <= n - 1)
- throw(ArgumentError(string("the requested diagonal, $k, must be at least ",
- "$(-n - 1) and at most $(n - 1) in an $n-by-$n matrix")))
- elseif k < 0
+ if k < 0
  fill!(A.data,0)
  return A
  elseif k == 0
@@ -262,10 +259,7 @@ triu!(A::UpperTriangular, k::Integer=0) = UpperTriangular(triu!(A.data,k))
 
 function tril!(A::UnitUpperTriangular{T}, k::Integer=0) where T
  n = size(A,1)
- if !(-n - 1 <= k <= n - 1)
- throw(ArgumentError(string("the requested diagonal, $k, must be at least ",
- "$(-n - 1) and at most $(n - 1) in an $n-by-$n matrix")))
- elseif k < 0
+ if k < 0
  fill!(A.data, zero(T))
  return UpperTriangular(A.data)
  elseif k == 0
@@ -291,10 +285,7 @@ end
 
 function triu!(A::LowerTriangular, k::Integer=0)
  n = size(A,1)
- if !(-n + 1 <= k <= n + 1)
- throw(ArgumentError(string("the requested diagonal, $k, must be at least ",
- "$(-n + 1) and at most $(n + 1) in an $n-by-$n matrix")))
- elseif k > 0
+ if k > 0
  fill!(A.data,0)
  return A
  elseif k == 0
@@ -311,10 +302,7 @@ tril!(A::LowerTriangular, k::Integer=0) = LowerTriangular(tril!(A.data,k))
 
 function triu!(A::UnitLowerTriangular{T}, k::Integer=0) where T
  n = size(A,1)
- if !(-n + 1 <= k <= n + 1)
- throw(ArgumentError(string("the requested diagonal, $k, must be at least ",
- "$(-n + 1) and at most $(n + 1) in an $n-by-$n matrix")))
- elseif k > 0
+ if k > 0
  fill!(A.data, zero(T))
  return LowerTriangular(A.data)
  elseif k == 0

stdlib/LinearAlgebra/test/dense.jl

@@ -141,14 +141,14 @@ bimg = randn(n,2)/2
  end
 end # for eltya
 
-@testset "test triu/tril bounds checking" begin
+@testset "test out of bounds triu/tril" begin
  local m, n = 5, 7
  ainit = rand(m, n)
  for a in (copy(ainit), view(ainit, 1:m, 1:n))
- @test_throws ArgumentError triu(a, -m)
- @test_throws ArgumentError triu(a, n + 2)
- @test_throws ArgumentError tril(a, -m - 2)
- @test_throws ArgumentError tril(a, n)
+ @test triu(a, -m) == a
+ @test triu(a, n + 2) == zero(a)
+ @test tril(a, -m - 2) == zero(a)
+ @test tril(a, n) == a
  end
 end
 
@@ -651,7 +651,7 @@ end
  2 6 10
  3 7 11
  4 8 12 ]
- @test_throws ArgumentError diag(A, -5)
+ @test diag(A,-5) == []
  @test diag(A,-4) == []
  @test diag(A,-3) == [4]
  @test diag(A,-2) == [3,8]
@@ -660,21 +660,21 @@ end
  @test diag(A, 1) == [5,10]
  @test diag(A, 2) == [9]
  @test diag(A, 3) == []
- @test_throws ArgumentError diag(A, 4)
+ @test diag(A, 4) == []
 
  @test diag(zeros(0,0)) == []
- @test_throws ArgumentError diag(zeros(0,0),1)
- @test_throws ArgumentError diag(zeros(0,0),-1)
+ @test diag(zeros(0,0),1) == []
+ @test diag(zeros(0,0),-1) == []
 
  @test diag(zeros(1,0)) == []
  @test diag(zeros(1,0),-1) == []
- @test_throws ArgumentError diag(zeros(1,0),1)
- @test_throws ArgumentError diag(zeros(1,0),-2)
+ @test diag(zeros(1,0),1) == []
+ @test diag(zeros(1,0),-2) == []
 
  @test diag(zeros(0,1)) == []
  @test diag(zeros(0,1),1) == []
- @test_throws ArgumentError diag(zeros(0,1),-1)
- @test_throws ArgumentError diag(zeros(0,1),2)
+ @test diag(zeros(0,1),-1) == []
+ @test diag(zeros(0,1),2) == []
 end
 
 @testset "Matrix to real power" for elty in (Float64, Complex{Float64})

stdlib/LinearAlgebra/test/triangular.jl

@@ -117,24 +117,24 @@ for elty1 in (Float32, Float64, BigFloat, ComplexF32, ComplexF64, Complex{BigFlo
  @test tril(A1,0) == A1
  @test tril(A1,-1) == LowerTriangular(tril(Matrix(A1), -1))
  @test tril(A1,1) == t1(tril(tril(Matrix(A1), 1)))
- @test_throws ArgumentError tril!(A1, -n - 2)
- @test_throws ArgumentError tril!(A1, n)
+ @test tril(A1, -n - 2) == zeros(size(A1))
+ @test tril(A1, n) == A1
  @test triu(A1,0) == t1(diagm(0 => diag(A1)))
  @test triu(A1,-1) == t1(tril(triu(A1.data,-1)))
  @test triu(A1,1) == zeros(size(A1)) # or just @test iszero(triu(A1,1))?
- @test_throws ArgumentError triu!(A1, -n)
- @test_throws ArgumentError triu!(A1, n + 2)
+ @test triu(A1, -n) == A1
+ @test triu(A1, n + 2) == zeros(size(A1))
  else
  @test triu(A1,0) == A1
  @test triu(A1,1) == UpperTriangular(triu(Matrix(A1), 1))
  @test triu(A1,-1) == t1(triu(triu(Matrix(A1), -1)))
- @test_throws ArgumentError triu!(A1, -n)
- @test_throws ArgumentError triu!(A1, n + 2)
+ @test triu(A1, -n) == A1
+ @test triu(A1, n + 2) == zeros(size(A1))
  @test tril(A1,0) == t1(diagm(0 => diag(A1)))
  @test tril(A1,1) == t1(triu(tril(A1.data,1)))
  @test tril(A1,-1) == zeros(size(A1)) # or just @test iszero(tril(A1,-1))?
- @test_throws ArgumentError tril!(A1, -n - 2)
- @test_throws ArgumentError tril!(A1, n)
+ @test tril(A1, -n - 2) == zeros(size(A1))
+ @test tril(A1, n) == A1
  end
 
  # factorize

stdlib/SparseArrays/src/linalg.jl

@@ -472,10 +472,6 @@ rdiv!(A::SparseMatrixCSC{T}, transD::Transpose{<:Any,<:Diagonal{T}}) where {T} =
 
 function triu(S::SparseMatrixCSC{Tv,Ti}, k::Integer=0) where {Tv,Ti}
  m,n = size(S)
- if !(-m + 1 <= k <= n + 1)
- throw(ArgumentError(string("the requested diagonal, $k, must be at least ",
- "$(-m + 1) and at most $(n + 1) in an $m-by-$n matrix")))
- end
  colptr = Vector{Ti}(undef, n+1)
  nnz = 0
  for col = 1 : min(max(k+1,1), n+1)
@@ -504,10 +500,6 @@ end
 
 function tril(S::SparseMatrixCSC{Tv,Ti}, k::Integer=0) where {Tv,Ti}
  m,n = size(S)
- if !(-m - 1 <= k <= n - 1)
- throw(ArgumentError(string("the requested diagonal, $k, must be at least ",
- "$(-m - 1) and at most $(n - 1) in an $m-by-$n matrix")))
- end
  colptr = Vector{Ti}(undef, n+1)
  nnz = 0
  colptr[1] = 1

stdlib/SparseArrays/src/sparsematrix.jl

@@ -1251,20 +1251,10 @@ function fkeep!(A::SparseMatrixCSC, f, trim::Bool = true)
  A
 end
 
-function tril!(A::SparseMatrixCSC, k::Integer = 0, trim::Bool = true)
- if !(-A.m - 1 <= k <= A.n - 1)
- throw(ArgumentError(string("the requested diagonal, $k, must be at least ",
- "$(-A.m - 1) and at most $(A.n - 1) in an $(A.m)-by-$(A.n) matrix")))
- end
+tril!(A::SparseMatrixCSC, k::Integer = 0, trim::Bool = true) =
  fkeep!(A, (i, j, x) -> i + k >= j, trim)
-end
-function triu!(A::SparseMatrixCSC, k::Integer = 0, trim::Bool = true)
- if !(-A.m + 1 <= k <= A.n + 1)
- throw(ArgumentError(string("the requested diagonal, $k, must be at least ",
- "$(-A.m + 1) and at most $(A.n + 1) in an $(A.m)-by-$(A.n) matrix")))
- end
+triu!(A::SparseMatrixCSC, k::Integer = 0, trim::Bool = true) =
  fkeep!(A, (i, j, x) -> j >= i + k, trim)
-end
 
 droptol!(A::SparseMatrixCSC, tol; trim::Bool = true) =
  fkeep!(A, (i, j, x) -> abs(x) > tol, trim)
@@ -3354,10 +3344,6 @@ end
 function diag(A::SparseMatrixCSC{Tv,Ti}, d::Integer=0) where {Tv,Ti}
  m, n = size(A)
  k = Int(d)
- if !(-m <= k <= n)
- throw(ArgumentError(string("requested diagonal, $k, must be at least $(-m) ",
- "and at most $n in an $m-by-$n matrix")))
- end
  l = k < 0 ? min(m+k,n) : min(n-k,m)
  r, c = k <= 0 ? (-k, 0) : (0, k) # start row/col -1
  ind = Vector{Ti}()

stdlib/SparseArrays/test/sparse.jl

@@ -1553,14 +1553,10 @@ end
  @test Array(tril(A,1)) == tril(AF,1)
  @test Array(triu!(copy(A), 2)) == triu(AF,2)
  @test Array(tril!(copy(A), 2)) == tril(AF,2)
- @test_throws ArgumentError tril(A, -n - 2)
- @test_throws ArgumentError tril(A, n)
- @test_throws ArgumentError triu(A, -n)
- @test_throws ArgumentError triu(A, n + 2)
- @test_throws ArgumentError tril!(sparse([1,2,3], [1,2,3], [1,2,3], 3, 4), -5)
- @test_throws ArgumentError tril!(sparse([1,2,3], [1,2,3], [1,2,3], 3, 4), 4)
- @test_throws ArgumentError triu!(sparse([1,2,3], [1,2,3], [1,2,3], 3, 4), -3)
- @test_throws ArgumentError triu!(sparse([1,2,3], [1,2,3], [1,2,3], 3, 4), 6)
+ @test tril(A, -n - 2) == zero(A)
+ @test tril(A, n) == A
+ @test triu(A, -n) == A
+ @test triu(A, n + 2) == zero(A)
 
  # fkeep trim option
  @test isequal(length(tril!(sparse([1,2,3], [1,2,3], [1,2,3], 3, 4), -1).rowval), 0)