Book Image

Data Science Using Python and R

By : Chantal D. Larose, Daniel T. Larose
Book Image

Data Science Using Python and R

By: Chantal D. Larose, Daniel T. Larose

Overview of this book

Data science is hot. Bloomberg named a data scientist as the ‘hottest job in America’. Python and R are the top two open-source data science tools using which you can produce hands-on solutions to real-world business problems, using state-of-the-art techniques. Each chapter in the book presents step-by-step instructions and walkthroughs for solving data science problems using Python and R. You’ll learn how to prepare data, perform exploratory data analysis, and prepare to model the data. As you progress, you’ll explore what are decision trees and how to use them. You’ll also learn about model evaluation, misclassification costs, naïve Bayes classification, and neural networks. The later chapters provide comprehensive information about clustering, regression modeling, dimension reduction, and association rules mining. The book also throws light on exciting new topics, such as random forests and general linear models. The book emphasizes data-driven error costs to enhance profitability, which avoids the common pitfalls that may cost a company millions of dollars. By the end of this book, you’ll have enough knowledge and confidence to start providing solutions to data science problems using R and Python.
Table of Contents (20 chapters)
Free Chapter
1
ABOUT THE AUTHORS
17
INDEX
18
END USER LICENSE AGREEMENT

11.4 HOW TO PERFORM MULTIPLE REGRESSION MODELING USING PYTHON

First, as always, we load the required packages.

import pandas as pd
import numpy as np
import statsmodels.api as sm

Next, we import the clothing_sales_training and clothing_sales_test data sets as sales_train and sales_test, respectively.

sales_train = pd.read_csv("C:/.../clothing_sales_training.csv")
sales_test = pd.read_csv("C:/.../clothing_sales_test.csv")

For simplicity, we separate the predictor variables and the target variable. We call the data frame of predictor variables X and the target variable y.

X = pd.DataFrame(sales_train[['CC', 'Days', 'Web']])
y = pd.DataFrame(sales_train[['Sales per Visit']])

To have a constant term b0 in our regression model, we need to add a constant variable to our predictor variables.

X = sm.add_constant(X)

Running the add_constant() command on the X variables will add a column to the data frame filled with the value...