Add tool to plot E vs. c for 3 phases (#16)

Make plotEnergyVsCompositionThreePhase more flexible

drivers/plotEnergyVsCompositionThreePhase.cc

@@ -8,6 +8,8 @@ namespace pt = boost::property_tree;
 
 int main(int argc, char* argv[])
 {
+    std::string databasename(argv[1]);
+
     Thermo4PFM::EnergyInterpolationType energy_interp_func_type
         = Thermo4PFM::EnergyInterpolationType::PBG;
     Thermo4PFM::ConcInterpolationType conc_interp_func_type
@@ -18,11 +20,11 @@ int main(int argc, char* argv[])
     // Cannot be 0 as it would trigger nans in f(T) evaluations
     double temperature = 1.e-8;
 
-    std::cout << " Read CALPHAD database..." << std::endl;
+    std::cout << " Read CALPHAD database " << databasename << std::endl;
     pt::ptree calphad_db;
     try
     {
-        pt::read_json("../thermodynamic_data/calphad3phases.json", calphad_db);
+        pt::read_json(databasename, calphad_db);
     }
     catch (std::exception& e)
     {

utils/FvsCbinaryThreePhases.plt

@@ -0,0 +1,12 @@
+set terminal png
+set pointsize 2
+set size 0.7,0.7
+
+set output "FvsC.png"
+set xlabel "Composition"
+set ylabel "Energy (J/mol)"
+
+plot 'FvsC.dat' i 0 u 1:2 t 'phase 1' w lines lw 2, \
+     'FvsC.dat' i 1 u 1:2 t 'phase 2' w lines lw 2, \
+     'FvsC.dat' i 2 u 1:2 t 'phase 3' w lines lw 2
+