示例#1
0
def main():

    # Load temperature data
    data = pd.read_csv('mlfromscratch/data/TempLinkoping2016.txt', sep="\t")

    time = np.atleast_2d(data["time"].values).T
    temp = data["temp"].values

    X = time  # fraction of the year [0, 1]
    y = temp

    X_train, X_test, y_train, y_test = train_test_split(X, y, test_size=0.4)

    poly_degree = 13

    model = ElasticNet(degree=15,
                       reg_factor=0.01,
                       l1_ratio=0.7,
                       learning_rate=0.001,
                       n_iterations=4000)
    model.fit(X_train, y_train)

    # Training error plot
    n = len(model.training_errors)
    training, = plt.plot(range(n),
                         model.training_errors,
                         label="Training Error")
    plt.legend(handles=[training])
    plt.title("Error Plot")
    plt.ylabel('Mean Squared Error')
    plt.xlabel('Iterations')
    plt.show()

    y_pred = model.predict(X_test)
    mse = mean_squared_error(y_test, y_pred)
    print("Mean squared error: %s (given by reg. factor: %s)" % (mse, 0.05))

    y_pred_line = model.predict(X)

    # Color map
    cmap = plt.get_cmap('viridis')

    # Plot the results
    m1 = plt.scatter(366 * X_train, y_train, color=cmap(0.9), s=10)
    m2 = plt.scatter(366 * X_test, y_test, color=cmap(0.5), s=10)
    plt.plot(366 * X,
             y_pred_line,
             color='black',
             linewidth=2,
             label="Prediction")
    plt.suptitle("Elastic Net")
    plt.title("MSE: %.2f" % mse, fontsize=10)
    plt.xlabel('Day')
    plt.ylabel('Temperature in Celcius')
    plt.legend((m1, m2), ("Training data", "Test data"), loc='lower right')
    plt.show()
示例#2
0
def main():

    X, y = make_regression(n_samples=100, n_features=1, noise=20)

    X_train, X_test, y_train, y_test = train_test_split(X, y, test_size=0.4)

    n_samples, n_features = np.shape(X)

    model = LinearRegression(n_iterations=100)

    model.fit(X_train, y_train)

    # Training error plot
    n = len(model.training_errors)
    training, = plt.plot(range(n),
                         model.training_errors,
                         label="Training Error")
    plt.legend(handles=[training])
    plt.title("Error Plot")
    plt.ylabel('Mean Squared Error')
    plt.xlabel('Iterations')
    plt.show()

    y_pred = model.predict(X_test)
    mse = mean_squared_error(y_test, y_pred)
    print("Mean squared error: %s" % (mse))

    y_pred_line = model.predict(X)

    # Color map
    cmap = plt.get_cmap('viridis')

    # Plot the results
    m1 = plt.scatter(366 * X_train, y_train, color=cmap(0.9), s=10)
    m2 = plt.scatter(366 * X_test, y_test, color=cmap(0.5), s=10)
    plt.plot(366 * X,
             y_pred_line,
             color='black',
             linewidth=2,
             label="Prediction")
    plt.suptitle("Linear Regression")
    plt.title("MSE: %.2f" % mse, fontsize=10)
    plt.xlabel('Day')
    plt.ylabel('Temperature in Celcius')
    plt.legend((m1, m2), ("Training data", "Test data"), loc='lower right')
    plt.show()
示例#3
0
def main():

    print ("-- Regression Tree --")

    # Load temperature data
    data = pd.read_csv('mlfromscratch/data/TempLinkoping2016.txt', sep="\t")

    time = np.atleast_2d(data["time"].values).T
    temp = np.atleast_2d(data["temp"].values).T

    X = standardize(time)        # Time. Fraction of the year [0, 1]
    y = temp[:, 0]  # Temperature. Reduce to one-dim

    X_train, X_test, y_train, y_test = train_test_split(X, y, test_size=0.3)

    model = RegressionTree()
    model.fit(X_train, y_train)
    y_pred = model.predict(X_test)

    y_pred_line = model.predict(X)

    # Color map
    cmap = plt.get_cmap('viridis')

    mse = mean_squared_error(y_test, y_pred)

    print ("Mean Squared Error:", mse)

    # Plot the results
    # Plot the results
    m1 = plt.scatter(366 * X_train, y_train, color=cmap(0.9), s=10)
    m2 = plt.scatter(366 * X_test, y_test, color=cmap(0.5), s=10)
    m3 = plt.scatter(366 * X_test, y_pred, color='black', s=10)
    plt.suptitle("Regression Tree")
    plt.title("MSE: %.2f" % mse, fontsize=10)
    plt.xlabel('Day')
    plt.ylabel('Temperature in Celcius')
    plt.legend((m1, m2, m3), ("Training data", "Test data", "Prediction"), loc='lower right')
    plt.show()
示例#4
0
def main():

    # Load temperature data
    data = pd.read_csv('mlfromscratch/data/TempLinkoping2016.txt', sep="\t")

    time = np.atleast_2d(data["time"].values).T
    temp = data["temp"].values

    X = time  # fraction of the year [0, 1]
    y = temp

    X_train, X_test, y_train, y_test = train_test_split(X, y, test_size=0.4)

    poly_degree = 15

    # Finding regularization constant using cross validation
    lowest_error = float("inf")
    best_reg_factor = None
    print("Finding regularization constant using cross validation:")
    k = 10
    for reg_factor in np.arange(0, 0.1, 0.01):
        cross_validation_sets = k_fold_cross_validation_sets(X_train,
                                                             y_train,
                                                             k=k)
        mse = 0
        for _X_train, _X_test, _y_train, _y_test in cross_validation_sets:
            model = PolynomialRidgeRegression(degree=poly_degree,
                                              reg_factor=reg_factor,
                                              learning_rate=0.001,
                                              n_iterations=10000)
            model.fit(_X_train, _y_train)
            y_pred = model.predict(_X_test)
            _mse = mean_squared_error(_y_test, y_pred)
            mse += _mse
        mse /= k

        # Print the mean squared error
        print("\tMean Squared Error: %s (regularization: %s)" %
              (mse, reg_factor))

        # Save reg. constant that gave lowest error
        if mse < lowest_error:
            best_reg_factor = reg_factor
            lowest_error = mse

    # Make final prediction
    model = PolynomialRidgeRegression(degree=poly_degree,
                                      reg_factor=best_reg_factor,
                                      learning_rate=0.001,
                                      n_iterations=10000)
    model.fit(X_train, y_train)
    y_pred = model.predict(X_test)
    mse = mean_squared_error(y_test, y_pred)
    print("Mean squared error: %s (given by reg. factor: %s)" %
          (lowest_error, best_reg_factor))

    y_pred_line = model.predict(X)

    # Color map
    cmap = plt.get_cmap('viridis')

    # Plot the results
    m1 = plt.scatter(366 * X_train, y_train, color=cmap(0.9), s=10)
    m2 = plt.scatter(366 * X_test, y_test, color=cmap(0.5), s=10)
    plt.plot(366 * X,
             y_pred_line,
             color='black',
             linewidth=2,
             label="Prediction")
    plt.suptitle("Polynomial Ridge Regression")
    plt.title("MSE: %.2f" % mse, fontsize=10)
    plt.xlabel('Day')
    plt.ylabel('Temperature in Celcius')
    plt.legend((m1, m2), ("Training data", "Test data"), loc='lower right')
    plt.show()