Docs for PosDefException and SingularException (#31251)

JuliaLang · Mar 5, 2019 · 9656c44 · 9656c44
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diff --git a/stdlib/LinearAlgebra/docs/src/index.md b/stdlib/LinearAlgebra/docs/src/index.md
@@ -304,6 +304,8 @@ Linear algebra functions in Julia are largely implemented by calling functions f
 ```@docs
 Base.:*(::AbstractMatrix, ::AbstractMatrix)
 Base.:\(::AbstractMatrix, ::AbstractVecOrMat)
+LinearAlgebra.SingularException
+LinearAlgebra.PosDefException
 LinearAlgebra.dot
 LinearAlgebra.cross
 LinearAlgebra.factorize

diff --git a/stdlib/LinearAlgebra/src/exceptions.jl b/stdlib/LinearAlgebra/src/exceptions.jl
@@ -29,10 +29,24 @@ function Base.showerror(io::IO, ex::ARPACKException)
     end
 end
 
+"""
+    SingularException
+
+Exception thrown when the input matrix has one or more zero-valued eigenvalues, and is not invertible.
+A linear solve involving such a matrix cannot be computed.
+The `info` field indicates the location of (one of) the singular value(s).
+"""
 struct SingularException <: Exception
     info::BlasInt
 end
 
+"""
+    PosDefException
+
+Exception thrown when the input matrix was not [positive definite](https://en.wikipedia.org/wiki/Definiteness_of_a_matrix).
+Some linear algebra functions and factorizations are only applicable to positive definite matrices.
+The `info` field indicates the location of (one of) the eigenvalue(s) which is (are) less than/equal to 0.
+"""
 struct PosDefException <: Exception
     info::BlasInt
 end