klappt nicht

uebungen/uebung3.py

@@ -1,42 +1,110 @@
+from typing import Tuple
+
 import numpy as np
+import pandas as pd
+import matplotlib.pyplot as plt
 
-visible = np.ones((10,1))
-hidden = np.ones((5,1))
 
-visible_bias = np.ones((len(visible), 1)) * 0.1
-hidden_bias = np.ones((len(hidden),1)) * 0.1
+def load_data():
+    df_orig_train = pd.read_csv('mnist_test_final.csv')
+    df_digits = df_orig_train.drop('label',axis=1)
 
-weights = np.random.rand(len(visible), len(hidden))
-phases = 1
+    return df_digits.to_numpy()
 
-learnrate = 0.2
+mnist = load_data()
 
 def sigmoid(x):
-    return 1 / (1 + np.exp(-x))  # Sigmoidfunktion
+    return 1.0 / (1.0 + np.exp(-x))  # Sigmoidfunktion
 
+class RBM:
 
-for i in range(1):
-    activation = sigmoid(np.matmul(visible.T, weights) + hidden_bias)
+    def __init__(self, visible_size: int, hidden_size: int, learnrate: float=0.1) -> None:
+        self.learnrate = learnrate
+        self.visible_size = visible_size
+        self.hidden_size = hidden_size
+        self.k = 2
+        self.epochs = 10
 
-    # 2. Computer outer product vh
-    positive_gradient = np.matmul(visible, hidden.T)
+        self.reset()
 
-    t = sigmoid(np.matmul(weights, hidden) + visible_bias)
-    reconstructed = sigmoid(np.matmul(weights, hidden) + visible_bias)
+    def reset(self) -> None:
+        self.weights = np.random.randn(self.visible_size, self.hidden_size)
+        self.visible_bias = np.ones(self.visible_size) * 0.1
+        self.hidden_bias = np.ones(self.hidden_size) * 0.1
 
-    # 4. Computer outer product v'h'
-    negative_gradient = np.matmul(reconstructed.T, activation)
-    # 5. Update weight matrix using gradients
-
-    delta_weights = learnrate * (positive_gradient - negative_gradient)
-
-    # 6. Update bias for visible and hidden layer
+    def activate(self, v0):
+        return sigmoid(np.matmul(v0.T, self.weights) + self.hidden_bias)
+        
+    def reactivate(self, h0):
+        return sigmoid(np.matmul(self.weights, h0.T) + self.visible_bias)
     
-    delta_visible_bias = learnrate * (visible - reconstructed)
-    delta_hidden_bias = learnrate * (hidden - activation)
+    def contrastive_divergence(self, v0, h0, v1, h1):
+        postive_gradient = np.outer(v0, h0)
+        negative_gradient = np.outer(v1, h0)
+
+        self.weights += self.learnrate * (postive_gradient - negative_gradient)
+
+        return self.weights
+    
+    def gibbs(self, v0):
+        for _ in range(self.k):
+            hidden_probs = self.activate(v0)
+            h0 = np.random.rand(len(v0), self.hidden_size) < hidden_probs
+            visible_probs = self.sigmoid(np.dot(h0, self.weights.T) + self.visible_bias)
+            v0 = np.random.rand(len(v0), self.visible_size) < visible_probs
+        return v0, hidden_probs
+        
+    def train(self, v0):
+        for _ in range(self.epochs):
+            h0 = self.activate(v0) # Aktivieren versteckter Schicht
+            v1 = self.reactivate(h0) # Reaktivieren sichtbarer Schicht
+            h1 = self.activate(v1)
+
+            self.contrastive_divergence(v0, h0, v1, h1)
+            
+            self.visible_bias += self.learnrate * (v0 - v1)
+            self.hidden_bias += self.learnrate * (h0 - h1)
 
 
+        return h0, v1
+
+    def run(self, v0 : np.ndarray) -> Tuple[np.ndarray, np.ndarray]:
+        """run Runs the Restricted Boltzmann machine on some input vector v0.
+
+        Args:
+            v0 (np.ndarray): 1-dimensional Input vector
+
+        Returns:
+            Tuple[np.ndarray, np.ndarray]: (hidden activation, visible reactivation)
+        """
+        h0 = self.activate(v0)
+        v1 = self.reactivate(h0)
+
+        return h0, v1
 
 
+def validate(idx):
+
+    test = mnist[idx].flatten()
+    #rbm.reset()
+    rbm.train(test)
+    (hid, out) = rbm.run(test)
+
+    return (hid.reshape((28, 28)), out.reshape((28,28)))
 
 
+rbm = RBM(28**2, 28**2, 0.1)
+
+rows, columns = (4,4)
+fig = plt.figure(figsize=(10, 7))
+for i in range((rows * columns)):
+    if i % 2 == 0:
+        (hid, out) = validate(i)
+        fig.add_subplot(rows, columns, i+1) 
+        plt.imshow(hid, cmap='gray')
+        fig.add_subplot(rows, columns,  i+2) 
+        plt.imshow(out, cmap='gray')
+        plt.axis('off')
+
+plt.show()
+