Fix to LaRCsim interpolation code

Is this code still used? I don't know, but -Wall -Werror turned up a problem.

diff --git a/src/FDM/LaRCsim/IO360.cxx b/src/FDM/LaRCsim/IO360.cxx
index 3b10900903a22fa0847479aff183da77d4beed9a..00acb23e6af87b7480e9af6203087b3daefc5695 100644 (file)
--- a/src/FDM/LaRCsim/IO360.cxx
+++ b/src/FDM/LaRCsim/IO360.cxx
@@ -376,8 +376,8 @@ float FGNewEngine::Power_Mixture_Correlation(float thi_actual)
        }
        if((i == 0) && (AFR_actual < AFR[i])) {
            // Assume linear extrapolation of the slope between the first two points for points before the first point
-           dydx = (mixPerPow[i] - mixPerPow[i-1]) / (AFR[i] - AFR[i-1]);
-           mixPerPow_actual = mixPerPow[i] + dydx * (AFR_actual - AFR[i]);
+           dydx = (mixPerPow[1] - mixPerPow[0]) / (AFR[1] - AFR[0]);
+           mixPerPow_actual = mixPerPow[0] + dydx * (AFR_actual - AFR[0]);
            return mixPerPow_actual;
        }
        if(AFR_actual == AFR[i]) {