add inplace arguments and simplify internal functions

Author: ChrisRackauckas

src/jacobians.jl

@@ -2,28 +2,30 @@
 function finite_difference_jacobian(f, x::AbstractArray{<:Number},
     fdtype::DataType=Val{:central}, funtype::DataType=Val{:Real},
     wrappertype::DataType=Val{:Default},
-    fx::Union{Void,AbstractArray{<:Number}}=nothing, epsilon::Union{Void,AbstractArray{<:Real}}=nothing, returntype=eltype(x))
+    fx::Union{Void,AbstractArray{<:Number}}=nothing, epsilon::Union{Void,AbstractArray{<:Real}}=nothing, returntype=eltype(x),
+    inplace::DataType=Val{true})
 
     J = zeros(returntype, length(x), length(x))
     finite_difference_jacobian!(J, f, x, fdtype, funtype, wrappertype, fx,
-                                epsilon, returntype)
+                                epsilon, returntype,inplace)
 end
 
 function finite_difference_jacobian!(J::AbstractMatrix{<:Number}, f,
     x::AbstractArray{<:Number},
     fdtype::DataType=Val{:central}, funtype::DataType=Val{:Real},
     wrappertype::DataType=Val{:Default},
     fx::Union{Void,AbstractArray{<:Number}}=nothing,
-    epsilon::Union{Void,AbstractArray{<:Number}}=nothing, returntype=eltype(x))
+    epsilon::Union{Void,AbstractArray{<:Number}}=nothing, returntype=eltype(x),
+    inplace::DataType=Val{true})
 
-    finite_difference_jacobian!(J, f, x, fdtype, funtype, wrappertype, fx, epsilon, returntype)
+    finite_difference_jacobian!(J, f, x, fdtype, funtype, wrappertype, fx,
+                                epsilon, returntype, inplace)
 end
 
 function finite_difference_jacobian!(J::AbstractMatrix{<:Real}, f,
     x::AbstractArray{<:Real},
     fdtype::DataType, ::Type{Val{:Real}}, ::Type{Val{:Default}},
-    fx::Union{Void,AbstractArray{<:Real}}=nothing,
-    epsilon::Union{Void,AbstractArray{<:Real}}=nothing, returntype=eltype(x))
+    fx, epsilon, returntype=eltype(x), inplace::Type{Val{true}})
 
     # TODO: test and rework this to support GPUArrays and non-indexable types, if possible
     m, n = size(J)
@@ -69,7 +71,7 @@ end
 function finite_difference_jacobian!(J::AbstractMatrix{<:Number}, f,
     x::AbstractArray{<:Number},
     fdtype::DataType, ::Type{Val{:Complex}}, ::Type{Val{:Default}},
-    fx::Union{Void,AbstractArray{<:Number}}=nothing, epsilon::Union{Void,AbstractArray{<:Real}}=nothing, returntype=eltype(x))
+    fx, epsilon, returntype, inplace::Type{Val{true}})
 
     # TODO: test and rework this to support GPUArrays and non-indexable types, if possible
     m, n = size(J)