December 2018
Beginner to intermediate
684 pages
21h 9m
English
The lasso implementation looks very similar to the ridge model we just ran. The main difference is that lasso needs to arrive at a solution using iterative coordinate descent whereas ridge can rely on a closed-form solution:
nfolds = 250alphas = np.logspace(-8, -2, 13)scaler = StandardScaler()lasso_results, lasso_coeffs = pd.DataFrame(), pd.DataFrame()for i, alpha in enumerate(alphas): coeffs, test_results = [], [] lr_lasso = Lasso(alpha=alpha) for i, (train_dates, test_dates) in enumerate(time_series_split(dates, nfolds=nfolds)): X_train = model_data.loc[idx[train_dates], features] y_train = model_data.loc[idx[train_dates], target] lr_lasso.fit(X=scaler.fit_transform(X_train), y=y_train) X_test = model_data.loc[idx[test_dates] ...