added comments on the units

sample_script.py

@@ -14,10 +14,11 @@
 # sys.path.insert(0, '/scratch/shannon/c/aether/Projects/Flow_Reconstruction_development/Codes/Python/')
 from DensityIntegrationUncertaintyQuantification import Density_integration_Poisson_uncertainty
 
-# Load the data:
+# Load the data: 
+# all loaded variables is in standard physical units: X, Y: [m], rho_x, rho_y: [kg/m^4] 
 data = loadmat('sample-data.mat', squeeze_me=True)
 
-# set the density uncertainty at the boundary points
+# set the density uncertainty at the boundary points [kg/m^3]
 sigma_rho_dirichlet = 0.01
 
 # calculate density and uncertainty