Feature Scaling and Normalization - Lab

Introduction

In this lab, you'll practice your feature scaling and normalization skills!

Objectives

You will be able to:

• Identify if it is necessary to perform log transformations on a set of features
• Perform log transformations on different features of a dataset
• Determine if it is necessary to perform normalization/standardization for a specific model or set of data
• Compare the different standardization and normalization techniques
• Use standardization/normalization on features of a dataset

Back to the Ames Housing data

Let's import our Ames Housing data.

import pandas as pd
import matplotlib.pyplot as plt
%matplotlib inline
plt.style.use('seaborn')

ames = pd.read_csv('ames.csv')

Look at the histograms for the continuous variables

Since there are so many features it is helpful to filter the columns by datatype and number of unique values. A heuristic you might use to select continous variables might be a combination of features that are not object datatypes and have at least a certain amount of unique values.

# Your code here

We can see from our histogram of the contiuous features that there are many examples where there are a ton of zeros. For example, WoodDeckSF (square footage of a wood deck) gives us a positive number indicating the size of the deck and zero if no deck exists. It might have made sense to categorize this variable to "deck exists or not (binary variable 1/0). Now you have a zero-inflated variable which is cumbersome to work with.

Lets drop these zero-inflated variables for now and select the features which don't have this characteristic.

# Select non zero-inflated continuous features as ames_cont
ames_cont = None

Perform log transformations for the variables where it makes sense

# Your code here

Standardize the continuous variables

Store your final features in a DataFrame features_final:

# Your code here

Summary

Great! You've now got some hands-on practice transforming data using log transforms, feature scaling, and normalization!