18267 1x1 NaN matrix eigenvalue (#18526)

* updated tests so that all of NaN, NaN16, and NaN32 are tested

* changed the indicies of the loop in issymmetric to include the diagonal.

base/linalg/eigen.jl

@@ -27,7 +27,7 @@ isposdef(A::Union{Eigen,GeneralizedEigen}) = isreal(A.values) && all(A.values .>
 
 function eigfact!{T<:BlasReal}(A::StridedMatrix{T}; permute::Bool=true, scale::Bool=true)
  n = size(A, 2)
- n==0 && return Eigen(zeros(T, 0), zeros(T, 0, 0))
+ n == 0 && return Eigen(zeros(T, 0), zeros(T, 0, 0))
  issymmetric(A) && return eigfact!(Symmetric(A))
  A, WR, WI, VL, VR, _ = LAPACK.geevx!(permute ? (scale ? 'B' : 'P') : (scale ? 'S' : 'N'), 'N', 'V', 'N', A)
  all(WI .== 0.) && return Eigen(WR, VR)

base/linalg/generic.jl

@@ -704,7 +704,7 @@ function issymmetric(A::AbstractMatrix)
  if indsm != indsn
  return false
  end
- for i = first(indsn):last(indsn)-1, j = (i+1):last(indsn)
+ for i = first(indsn):last(indsn), j = (i):last(indsn)
  if A[i,j] != transpose(A[j,i])
  return false
  end

test/linalg/eigen.jl

@@ -95,6 +95,16 @@ for eltya in (Float32, Float64, Complex64, Complex128, Int)
  @test v == f[:vectors]
  end
 end
+
+#test eigenvalue computations with NaNs
+for eltya in (NaN16, NaN32, NaN)
+ @test_throws(ArgumentError, eig(fill(eltya, 1, 1)))
+ @test_throws(ArgumentError, eig(fill(eltya, 2, 2)))
+ test_matrix = rand(typeof(eltya),3,3)
+ test_matrix[2,2] = eltya
+ @test_throws(ArgumentError, eig(test_matrix))
+end
+
 # test a matrix larger than 140-by-140 for #14174
 let aa = rand(200, 200)
  for atype in ("Array", "SubArray")