Traceback (most recent call last): File "/Users/mhjensen/miniforge3/envs/myenv/lib/python3.9/site-packages/jupyter_cache/executors/utils.py", line 51, in single_nb_execution executenb( File "/Users/mhjensen/miniforge3/envs/myenv/lib/python3.9/site-packages/nbclient/client.py", line 1204, in execute return NotebookClient(nb=nb, resources=resources, km=km, **kwargs).execute() File "/Users/mhjensen/miniforge3/envs/myenv/lib/python3.9/site-packages/nbclient/util.py", line 84, in wrapped return just_run(coro(*args, **kwargs)) File "/Users/mhjensen/miniforge3/envs/myenv/lib/python3.9/site-packages/nbclient/util.py", line 62, in just_run return loop.run_until_complete(coro) File "/Users/mhjensen/miniforge3/envs/myenv/lib/python3.9/asyncio/base_events.py", line 642, in run_until_complete return future.result() File "/Users/mhjensen/miniforge3/envs/myenv/lib/python3.9/site-packages/nbclient/client.py", line 663, in async_execute await self.async_execute_cell( File "/Users/mhjensen/miniforge3/envs/myenv/lib/python3.9/site-packages/nbclient/client.py", line 965, in async_execute_cell await self._check_raise_for_error(cell, cell_index, exec_reply) File "/Users/mhjensen/miniforge3/envs/myenv/lib/python3.9/site-packages/nbclient/client.py", line 862, in _check_raise_for_error raise CellExecutionError.from_cell_and_msg(cell, exec_reply_content) nbclient.exceptions.CellExecutionError: An error occurred while executing the following cell: ------------------ from sklearn import linear_model np.random.seed(2018) n = 10 d = 2 Lambda = 0.01 # Make data set. x = np.linspace(-3, 3, n) y = 2.0 + 0.5*x + 5.0*(x**2)+ np.random.randn(n) # Design matrix X does not include the intercept. X = np.zeros((n, d)) for p in range(d): X[:, p] = x ** (p+1) #Split data in train and test X_train, X_test, y_train, y_test = train_test_split(X, y, test_size=0.2) # Scale data by subtracting mean value of the input using scikit-learn scaler = StandardScaler(with_std=False) scaler.fit(X_train) X_train_mean = np.mean(X_train,axis=0) X_train_scaled = scaler.transform(X_train) X_test_scaled = scaler.transform(X_test) # We scale also the output, here by our own code y_scaler = np.mean(y_train) y_train_scaled = y_train - y_scaler y_test_scaled = y_test- y_scaler #Calculate beta OLS = LinearRegression() betaOLS=OLS.fit(X_train_scaled,y_train_scaled) ypredictOLS = OLS.predict(X_test_scaled) linear_model.Ridge(Lambda) RegRidge.fit(X_train_scaled,y_train_scaled) ypredictRidge = RegRidge.predict(X_test_scaled) betaOLS = OLS.coef_ betaRidge = RegRidge.coef_ print(betaOLS) print(betaRidge) interceptOLS = np.mean(y_train) - X_train_mean @ betaOLS interceptRidge = y_scaler - X_train_mean @ betaRidge print(interceptOLS) print(interceptRidge) #predict value ytilde_test_Ridge = X_test_scaled @ betaRidge+y_scaler ytilde_test_OLS = X_test_scaled @ betaOLS+y_scaler #Calculate MSE print(" ") print("test MSE of OLS") print(MSE(y_test,ytilde_test_OLS)) print(" ") print("test MSE of Ridge") print(MSE(y_test,ytilde_test_Ridge)) plt.scatter(x,y,label='Data') plt.plot(x, X @ RegRidge.coef_ + RegRidge.intercept_ , label="Ridge_Fit") plt.grid() plt.legend() plt.show() ------------------ --------------------------------------------------------------------------- NameError Traceback (most recent call last) Input In [11], in ()  32 ypredictOLS = OLS.predict(X_test_scaled)  33 linear_model.Ridge(Lambda) ---> 34 RegRidge.fit(X_train_scaled,y_train_scaled)  35 ypredictRidge = RegRidge.predict(X_test_scaled)  36 betaOLS = OLS.coef_ NameError: name 'RegRidge' is not defined NameError: name 'RegRidge' is not defined