Use CR adjoint for logdet(::Cholesky) (#1226)

* Use CR adjoint for `logdet(::Cholesky)`

* Update Project.toml

* Update ci.yml

* Update Project.toml

.github/workflows/ci.yml

@@ -17,7 +17,7 @@ jobs:
       fail-fast: false
       matrix:
         version:
-          - '1.3' # Replace this with the minimum Julia version that your package supports.
+          - '1.6' # Replace this with the minimum Julia version that your package supports.
           - '1'   # automatically expands to the latest stable 1.x release of Julia
           - 'nightly'
         os:

Project.toml

@@ -25,7 +25,7 @@ ZygoteRules = "700de1a5-db45-46bc-99cf-38207098b444"
 
 [compat]
 AbstractFFTs = "0.5, 1.0"
-ChainRules = "1.5"
+ChainRules = "1.33"
 ChainRulesCore = "1.9"
 ChainRulesTestUtils = "1"
 DiffRules = "1.4"
@@ -38,7 +38,7 @@ NaNMath = "0.3, 1"
 Requires = "1.1"
 SpecialFunctions = "1.6, 2"
 ZygoteRules = "0.2.1"
-julia = "1.3"
+julia = "1.6"
 
 [extras]
 CUDA = "052768ef-5323-5732-b1bb-66c8b64840ba"

src/lib/array.jl

@@ -741,12 +741,6 @@ end
   end
 end
 
-@adjoint function logdet(C::Cholesky)
-  return logdet(C), function(Δ)
-    return ((uplo=nothing, info=nothing, factors=Diagonal(2 .* Δ ./ diag(C.factors))),)
-  end
-end
-
 @adjoint function Matrix(S::UniformScaling, i::Integer, j::Integer)
   return Matrix(S, i, j), Δ -> ((λ=tr(Δ),), nothing, nothing)
 end