From 0f2e774a8b55f3841d28c691deb5869e835e5eb2 Mon Sep 17 00:00:00 2001
From: BriceonWiley <briceonwiley@rice.edu>
Date: Sat, 19 Dec 2020 22:17:40 -0600
Subject: [PATCH] updated to account for autodiff=false

---
 src/scalar.jl | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/src/scalar.jl b/src/scalar.jl
index dda7329bd..66ab6d4b5 100644
--- a/src/scalar.jl
+++ b/src/scalar.jl
@@ -1,4 +1,4 @@
-function solve(prob::NonlinearProblem{<:Number}, ::NewtonRaphson, args...; xatol = nothing, xrtol = nothing, maxiters = 1000, kwargs...)
+function solve(prob::NonlinearProblem{<:Number}, alg::NewtonRaphson, args...; xatol = nothing, xrtol = nothing, maxiters = 1000, kwargs...)
   f = Base.Fix2(prob.f, prob.p)
   x = float(prob.u0)
   T = typeof(x)
@@ -7,7 +7,12 @@ function solve(prob::NonlinearProblem{<:Number}, ::NewtonRaphson, args...; xatol
 
   xo = oftype(x, Inf)
   for i in 1:maxiters
-    fx, dfx = value_derivative(f, x)
+    if alg_autodiff(alg)
+      fx, dfx = value_derivative(f, x)
+    else
+      fx = f(x)
+      dfx = FiniteDiff.finite_difference_derivative(f, x, alg.diff_type, eltype(x), fx)
+    end
     iszero(fx) && return NewtonSolution(x, DEFAULT)
     Δx = dfx \ fx
     x -= Δx