feat(src): Add confusion matrix plotting function for model evaluation

code/src/ml/model_selection.py

@@ -1,8 +1,9 @@
 import numpy as np
 import pandas as pd
 import os
-from sklearn.model_selection import train_test_split as sklearn_split
-
+import matplotlib.pyplot as plt
+from sklearn.metrics import confusion_matrix, ConfusionMatrixDisplay
+from joblib import load
 
 def create_ready_data(
     stft_data_path: str,
@@ -121,6 +122,7 @@ def train_and_evaluate_model(
 
         try:
             y_pred = model.predict(x_test)
+            result["y_pred"] = y_pred  # Convert to numpy array
         except Exception as e:
             result["error"] = f"Prediction error: {str(e)}"
             return result
@@ -153,3 +155,45 @@ def train_and_evaluate_model(
     except Exception as e:
         result["error"] = f"Training error: {str(e)}"
         return result
+def plot_confusion_matrix(results_sensor, x_test, y_test):
+    """
+    Plot confusion matrices for each model in results_sensor1.
+
+    Parameters:
+    -----------
+    results_sensor1 : list
+        List of dictionaries containing model results.
+    x_test1 : array-like
+        Test input samples.
+    y_test : array-like
+        True labels for the test samples.
+
+    Returns:
+    --------
+    None
+    This function will display confusion matrices for each model in results_sensor1.
+
+    Example
+    -------
+    >>> results_sensor1 = [
+    ...     {'model': 'model1', 'accuracy': 95.0},
+    ...     {'model': 'model2', 'accuracy': 90.0}
+    ... ]
+    >>> x_test1 = np.random.rand(100, 10)  # Example test data
+    >>> y_test = np.random.randint(0, 2, size=100)  # Example true labels
+    >>> plot_confusion_matrix(results_sensor1, x_test1, y_test)
+    """
+    # Iterate through each model result and plot confusion matrix
+    for i in results_sensor:
+        model = load(f"D:/thesis/models/{i['sensor']}/{i['model']}.joblib")
+        y_pred = model.predict(x_test)
+        cm = confusion_matrix(y_test, y_pred) # -> ndarray
+
+        # get the class labels
+        labels = model.classes_
+
+        # Plot
+        disp = ConfusionMatrixDisplay(confusion_matrix=cm, display_labels=labels)
+        disp.plot(cmap=plt.cm.Blues)  # You can change colormap
+        plt.title(f"{i['model']} {i['sensor']} Test")
+        plt.show()