From b557ffea650822220523a2a3fbdbd6671b161027 Mon Sep 17 00:00:00 2001
From: Christopher Rackauckas <accounts@chrisrackauckas.com>
Date: Tue, 27 Aug 2019 15:16:40 -0400
Subject: [PATCH] CuArray-compatible Jacobians

No color vectors
---
 src/back.jl | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/back.jl b/src/back.jl
index e638e1ad..e5acb9c5 100644
--- a/src/back.jl
+++ b/src/back.jl
@@ -173,7 +173,7 @@ Calculate the output jacobian `J = d/dx m(x)` such that each row `i` of `J` corr
 """
 function jacobian(f, x::AbstractVector)
   y::AbstractVector, back = forward(f, x)
-  ȳ(i) = [i == j for j = 1:length(y)]
+  ȳ(i) = false .* y .+ (1:length(y) .== i)
   vcat([transpose(back(ȳ(i))[1]) for i = 1:length(y)]...)
 end