diff --git a/src/mirco_setparameters.cpp b/src/mirco_setparameters.cpp
index 4beb8dc..ba664ad 100644
--- a/src/mirco_setparameters.cpp
+++ b/src/mirco_setparameters.cpp
@@ -4,6 +4,7 @@
 #include <Teuchos_ParameterList.hpp>
 #include <Teuchos_RCP.hpp>
 #include <Teuchos_XMLParameterListHelpers.hpp>
+#include <map>
 #include <string>
 #include <vector>
 
@@ -60,15 +61,16 @@ void MIRCO::SetParameters(double& E1, double& E2, double& LateralLength, double&
   // The following pressure based constants are calculated by solving a flat indentor problem using
   // the pressure based Green function described in Pohrt and Li (2014).
   // http://dx.doi.org/10.1134/s1029959914040109
-  const std::vector<double> shape_factors_pressure{0.961389237917602, 0.924715342432435,
-      0.899837531880697, 0.884976751041942, 0.876753783192863, 0.872397956576882, 0.871958228537090,
-      0.882669916668780};
+  const std::map<int, double> shape_factors_pressure{{1, 0.961389237917602}, {2, 0.924715342432435},
+      {3, 0.899837531880697}, {4, 0.884976751041942}, {5, 0.876753783192863},
+      {6, 0.872397956576882}, {7, 0.871958228537090}, {8, 0.882669916668780}};
 
   // The following force based constants are taken from Table 1 of Bonari et al. (2020).
   // https://doi.org/10.1007/s00466-019-01791-3
-  const std::vector<double> shape_factors_force{0.778958541513360, 0.805513388666376,
-      0.826126871395416, 0.841369158110513, 0.851733020725652, 0.858342234203154, 0.862368243479785,
-      0.864741597831785};
+  const std::map<int, double> shape_factors_force{{1, 0.778958541513360}, {2, 0.805513388666376},
+      {3, 0.826126871395416}, {4, 0.841369158110513}, {5, 0.851733020725652},
+      {6, 0.858342234203154}, {7, 0.862368243479785}, {8, 0.864741597831785}};
+
 
   // Setting up the geometrical parameters.
   Teuchos::ParameterList& geoParams =
@@ -83,11 +85,11 @@ void MIRCO::SetParameters(double& E1, double& E2, double& LateralLength, double&
 
   if (PressureGreenFunFlag)
   {
-    ShapeFactor = shape_factors_pressure[Resolution - 1];
+    ShapeFactor = shape_factors_pressure.at(Resolution);
   }
   else
   {
-    ShapeFactor = shape_factors_force[Resolution - 1];
+    ShapeFactor = shape_factors_force.at(Resolution);
   }
 
   ElasticComplianceCorrection = LateralLength * CompositeYoungs / ShapeFactor;