File Content: plot_ols.py #!/usr/bin/python # -*- coding: utf-8 -*- """ ========================================================= Linear Regression Example ========================================================= This example uses the only the first feature of the `diabetes` dataset, in order to illustrate a two-dimensional plot of this regression technique. The straight line can be seen in the plot, showing how linear regression attempts to draw a straight line that will best minimize the residual sum of squares between the observed responses in the dataset, and the responses predicted by the linear approximation. The coefficients, the residual sum of squares and the variance score are also calculated. """ print(__doc__) # Code source: Jaques Grobler # License: BSD 3 clause import matplotlib.pyplot as plt import numpy as np from sklearn import datasets, linear_model # Load the diabetes dataset diabetes = datasets.load_diabetes() # Use only one feature diabetes_X = diabetes.data[:, np.newaxis, 2] # Split the data into training/testing sets diabetes_X_train = diabetes_X[:-20] diabetes_X_test = diabetes_X[-20:] # Split the targets into training/testing sets diabetes_y_train = diabetes.target[:-20] diabetes_y_test = diabetes.target[-20:] # Create linear regression object regr = linear_model.LinearRegression() # Train the model using the training sets regr.fit(diabetes_X_train, diabetes_y_train) # The coefficients print('Coefficients: \n', regr.coef_) # The mean squared error print("Mean squared error: %.2f" % np.mean((regr.predict(diabetes_X_test) - diabetes_y_test) ** 2)) # Explained variance score: 1 is perfect prediction print('Variance score: %.2f' % regr.score(diabetes_X_test, diabetes_y_test)) # Plot outputs plt.scatter(diabetes_X_test, diabetes_y_test, color='black') plt.plot(diabetes_X_test, regr.predict(diabetes_X_test), color='blue', linewidth=3) plt.xticks(()) plt.yticks(()) plt.show() Submit