Fix theoretical POD error by using test data

src/e2_CreatePatches_POD.py

@@ -90,7 +90,8 @@ for R_ in R:
         test_velocity_predict, test_pressure_predict = RegressionModel.POD(
             R_velocity=R_,
             R_pressure=R_,
-            scaled=False
+            scaled=False,
+            testdata=True
         )
 
         # Iterate over each testcase

src/models/RegressionModels.py

@@ -79,7 +79,8 @@ class RegressionModels:
             self, 
             R_velocity=None, 
             R_pressure=None, 
-            scaled=True
+            scaled=True, 
+            testdata=False
         ) -> Tuple[np.ndarray, np.ndarray]:
         '''
         Perform Proper Orthogonal Decomposition (POD) on the velocity and pressure fields.
@@ -94,6 +95,8 @@ class RegressionModels:
             Number of modes for the pressure field, by default None
         scaled : bool, optional
             Use scaled data, by default True
+        testdata : bool, optional
+            Use test data, by default True
             
         Returns
         -------
@@ -105,13 +108,25 @@ class RegressionModels:
         if R_pressure is None:
             _, R_pressure = self.elbow_point(scaled=True)
         # Perform SVD
-        if scaled:
-            U_velocity, S_velocity, V_velocity = np.linalg.svd(self.velocity_matrix_scaled_train)
-            U_pressure, S_pressure, V_pressure = np.linalg.svd(self.pressure_matrix_scaled_train)
+        if testdata:
+            if scaled:
+                velocity_matrix = self.velocity_matrix_scaled_test
+                pressure_matrix = self.pressure_matrix_scaled_test
+            else:
+                velocity_matrix = self.velocity_matrix_test
+                pressure_matrix = self.pressure_matrix_test
         else:
-            U_velocity, S_velocity, V_velocity = np.linalg.svd(self.velocity_matrix_train)
-            U_pressure, S_pressure, V_pressure = np.linalg.svd(self.pressure_matrix_train)
-
+            if scaled:
+                velocity_matrix = self.velocity_matrix_scaled_train
+                pressure_matrix = self.pressure_matrix_scaled_train
+            else:
+                velocity_matrix = self.velocity_matrix_train
+                pressure_matrix = self.pressure_matrix_train
+
+        # Get the splitted matrices
+        U_velocity, S_velocity, V_velocity = np.linalg.svd(velocity_matrix)
+        U_pressure, S_pressure, V_pressure = np.linalg.svd(pressure_matrix)
+        
         # Extract reduced matrices
         U_r_velocity = U_velocity[:, :R_velocity]
         S_r_velocity = np.diag(S_velocity[:R_velocity])