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

10.5 HOW TO PERFORM k‐MEANS CLUSTERING USING PYTHON

Load the required packages.

import pandas as pd
from scipy import stats
from sklearn.cluster import KMeans

Read in the white_wine_training data set as wine_train.

wine_train = pd.read_csv("C:/.../white_wine_training")

For simplicity, let us isolate the predictor variables and save them as X.

X = wine_train[['alcohol', 'sugar']]

Once we have our predictor variables, standardize them using the z‐score transformation and save the result as a data frame.

Xz = pd.DataFrame(stats.zscore(X), columns=['alcohol', 'sugar'])

As in Chapter 3, the stats.zscore command will convert the variables in X into their z‐scores. We save the new standardized variables as a data frame using the DataFrame() command. The optional input columns use the given names as the column names. We save the result as Xz.

Now, we run k‐means clustering on the training data set.

kmeans01...