use undefmatrix to init jacobian

Author: oscarddssmith

Project.toml

@@ -19,7 +19,7 @@ StaticArraysCore = "1e83bf80-4336-4d27-bf5d-d5a4f845583c"
 UnPack = "3a884ed6-31ef-47d7-9d2a-63182c4928ed"
 
 [compat]
-ArrayInterfaceCore = "0.1.1"
+ArrayInterfaceCore = "0.1.22"
 DiffEqBase = "6"
 FiniteDiff = "2"
 ForwardDiff = "0.10.3"

src/raphson.jl

@@ -54,7 +54,7 @@ end
 
 function jacobian_caches(alg::NewtonRaphson, f, u, p, ::Val{true})
     uf = JacobianWrapper(f, p)
-    J = false .* u .* u'
+    J = ArrayInterfaceCore.undefmatrix(u)
 
     linprob = LinearProblem(J, _vec(zero(u)); u0 = _vec(zero(u)))
     weight = similar(u)