Implement isposdef

Author: lkdvos

src/tensors/factorizations/factorizations.jl

@@ -45,25 +45,6 @@ include("matrixalgebrakit.jl")
 include("truncation.jl")
 include("deprecations.jl")
 
-"""
-    isposdef(t::AbstractTensor, (leftind, rightind)::Index2Tuple) -> ::Bool
-
-Test whether a tensor `t` is positive definite as linear map from `rightind` to `leftind`.
-
-If `leftind` and `rightind` are not specified, the current partition of left and right
-indices of `t` is used. In that case, less memory is allocated if one allows the data in
-`t` to be destroyed/overwritten, by using `isposdef!(t)`. Note that the permuted tensor on
-which `isposdef!` is called should have equal domain and codomain, as otherwise it is
-meaningless.
-"""
-function LinearAlgebra.isposdef(t::AbstractTensorMap, (p₁, p₂)::Index2Tuple)
-    tcopy = permutedcopy_oftype(t, factorisation_scalartype(isposdef, t), p)
-    return isposdef!(tcopy)
-end
-function LinearAlgebra.isposdef(t::AbstractTensorMap)
-    tcopy = copy_oftype(t, float(scalartype(t)))
-    return isposdef!(tcopy)
-end
 
 function isisometry(t::AbstractTensorMap, (p₁, p₂)::Index2Tuple)
     t = permute(t, (p₁, p₂); copy=false)

src/tensors/factorizations/interface.jl

@@ -217,9 +217,21 @@ matrices. See the corresponding documentation for more information.
 See also [`eig(!)`](@ref eig) and [`eigh(!)`](@ref)
 """ eigen(::AbstractTensorMap), eigen!(::AbstractTensorMap)
 
+@doc """
+    isposdef(t::AbstractTensor, [(leftind, rightind)::Index2Tuple]) -> ::Bool
+
+Test whether a tensor `t` is positive definite as linear map from `rightind` to `leftind`.
+
+If `leftind` and `rightind` are not specified, the current partition of left and right
+indices of `t` is used. In that case, less memory is allocated if one allows the data in
+`t` to be destroyed/overwritten, by using `isposdef!(t)`. Note that the permuted tensor on
+which `isposdef!` is called should have equal domain and codomain, as otherwise it is
+meaningless.
+""" isposdef(::AbstractTensorMap), isposdef!(::AbstractTensorMap)
+
 for f in
     (:tsvd, :eig, :eigh, :eigen, :leftorth, :rightorth, :leftpolar, :rightpolar, :leftnull,
-     :rightnull)
+     :rightnull, :isposdef)
     f! = Symbol(f, :!)
     @eval function $f(t::AbstractTensorMap, p::Index2Tuple; kwargs...)
         tcopy = permutedcopy_oftype(t, factorisation_scalartype($f, t), p)