diff --git a/src/SimNDT/core/simulation.py b/src/SimNDT/core/simulation.py
index d7ebb5f..c21bea2 100644
--- a/src/SimNDT/core/simulation.py
+++ b/src/SimNDT/core/simulation.py
@@ -3,6 +3,9 @@
 """
 simulation.py
 
+"Numercial" Material grid: Simulation.Im derived from scenario.Iabs in create_numericalModel,
+                           just a resizing of Iabs (labeled material matrix)
+
 Created by Miguel Molero on 2013-09-30.
 Copyright (c) 2013 MMolero. All rights reserved.
 """
@@ -81,7 +84,7 @@ class Simulation:
         self.t = self.dt*np.arange(0,self.TimeSteps)
 
     def create_numericalModel(self, scenario):
-
+        print("Creating numerical simulation model (material labeled)")
         #Spatial Scale
         Pixel_mm = float(scenario.Pixel_mm)
 
@@ -91,6 +94,20 @@ class Simulation:
         self.Im = imresize(scenario.Iabs, self.Rgrid, interp='nearest')
         self.MRI, self.NRI = np.shape(self.Im)
 
+    def update_numericalModel(self, scenario, Im, Iabs):
+        print("Updating numerical simulation model (material labeled)")
+        #Spatial Scale
+        Pixel_mm = float(scenario.Pixel_mm)
+        if Im is not 0:
+          self.Im = Im
+          self.MRI, self.NRI = np.shape(self.Im)
+        if Iabs is not 0:
+          scenario.Iabs = Iabs
+          Mp = np.shape(scenario.Iabs)[0]*1e-3/Pixel_mm/self.dx
+          self.Rgrid = float(Mp/np.shape(scenario.Iabs)[0])
+          self.TapGrid = np.around(scenario.Tap * self.Rgrid)
+          self.Im = imresize(scenario.Iabs, self.Rgrid, interp='nearest')
+          self.MRI, self.NRI = np.shape(self.Im)
 
     def rotate_model(self, theta, scenario):
         Theta = theta * (180.0/np.pi) - 270.