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PySpark Cookbook

You're reading from  PySpark Cookbook

Product type Book
Published in Jun 2018
Publisher Packt
ISBN-13 9781788835367
Pages 330 pages
Edition 1st Edition
Languages
Authors (2):
Denny Lee Denny Lee
Profile icon Denny Lee
Tomasz Drabas Tomasz Drabas
Profile icon Tomasz Drabas
View More author details
Toc

Table of Contents (13) Chapters close

Title Page
Packt Upsell
Contributors
Preface
1. Installing and Configuring Spark 2. Abstracting Data with RDDs 3. Abstracting Data with DataFrames 4. Preparing Data for Modeling 5. Machine Learning with MLlib 6. Machine Learning with the ML Module 7. Structured Streaming with PySpark 8. GraphFrames – Graph Theory with PySpark Index

Standardizing the data


Data standardization (or normalization) is important for a number of reasons:

  • Some algorithms converge faster on standardized (or normalized) data
  • If your input variables are on vastly different scales, the interpretability of coefficients might be hard or conclusions drawn might be wrong
  • For some models, the optimal solution might be wrong if you do not standardize

In this recipe, we will show you how to standardize the data so if your modeling project requires standardized data, you will know how to do it.

Getting ready

To execute this recipe, you need to have a working Spark environment. You would have already gone through the previous recipe where we encoded the census data.

No other prerequisites are required.

How to do it...

MLlib offers a method to do most of this work for us. Even though the following code might be confusing at first, we will walk through it step by step:

standardizer = feat.StandardScaler(True, True)
sModel = standardizer.fit(final_data.map(lambda row...
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