From b395d41eb668205b9afc34879abd502e4f815b75 Mon Sep 17 00:00:00 2001
From: Axel Kohlmeyer <akohlmey@gmail.com>
Date: Fri, 5 Aug 2022 07:40:36 -0400
Subject: [PATCH] fix index copy-n-paste error

---
 lib/atc/FE_Element.cpp | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/lib/atc/FE_Element.cpp b/lib/atc/FE_Element.cpp
index a57484299b..8192fbc264 100644
--- a/lib/atc/FE_Element.cpp
+++ b/lib/atc/FE_Element.cpp
@@ -186,7 +186,7 @@ static const double localCoordinatesTolerance = 1.e-09;
       double c[3]={0,0,0};
       c[0] = y0*X[0] - y0*X[1] - y0*X[2] + y0*X[3] - x0*Y[0] + (X[1]*Y[0])*0.5 + (X[2]*Y[0])*0.5 + x0*Y[1] - (X[0]*Y[1])*0.5 - (X[3]*Y[1])*0.5 + x0*Y[2] - (X[0]*Y[2])*0.5 - (X[3]*Y[2])*0.5 - x0*Y[3] + (X[1]*Y[3])*0.5 + (X[2]*Y[3])*0.5;
       c[1] = -(y0*X[0]) + y0*X[1] - y0*X[2] + y0*X[3] + x0*Y[0] - X[1]*Y[0] - x0*Y[1] + X[0]*Y[1] + x0*Y[2] - X[3]*Y[2] - x0*Y[3] + X[2]*Y[3];
-      c[1] = (X[1]*Y[0])*0.5 - (X[2]*Y[0])*0.5 - (X[0]*Y[1])*0.5 + (X[3]*Y[1])*0.5 + (X[0]*Y[2])*0.5 - (X[3]*Y[2])*0.5 - (X[1]*Y[3])*0.5 + (X[2]*Y[3])*0.5;
+      c[2] = (X[1]*Y[0])*0.5 - (X[2]*Y[0])*0.5 - (X[0]*Y[1])*0.5 + (X[3]*Y[1])*0.5 + (X[0]*Y[2])*0.5 - (X[3]*Y[2])*0.5 - (X[1]*Y[3])*0.5 + (X[2]*Y[3])*0.5;
       double xi2[2]={0,0};
       int nroots = solve_quadratic(c,xi2);
       if (nroots == 0) throw ATC_Error("no real roots in 2D analytic projection guess");