Update app.py

app.py

@@ -47,7 +47,7 @@ k_test_train = rbf_kernel(x_test, x_train, lengthscale, variance)
 k_test_test = rbf_kernel(x_test, x_test, lengthscale, variance)
 
 k_train_with_noise = k_train_train + noise_variance * np.eye(3)
-c = np.linalg.inv(np.linalg.cholesky())
+c = np.linalg.inv(np.linalg.cholesky(k_train_with_noise))
 k_inv = np.dot(c.T,c)
 
 pred_mean = k_test_train@k_inv@y_train