Data Science Essentials in Python

Unit 49

Fitting a Linear Regression

Linear regression is a form of predictive statistical modeling that aims at explaining all or some of a variable’s variance using a linear model. It’s a supervised modeling technique: you must train (“fit”) the model before using it for prediction.

Ordinary Least Square Regression

Ordinary least squares (OLS) regression relates independent variables (predictors) and dependent variables (predicted value). The model treats the predicted value reg(x_i) as a linear combination of predictors x_i. The differences between the real y_i and predicted values are called residuals. In the case of a perfect fit, all residuals are zero. The sum of possibly weighted (with weights w_i>0) squared residuals, SSR, determines the ...