Book Image

QlikView for Developers Cookbook

By : Stephen Redmond
Book Image

QlikView for Developers Cookbook

By: Stephen Redmond

Overview of this book

QlikView has been around since 1993, but has only really taken off in recent years as a leader in the in-memory BI space and, more recently, in the data discovery area. QlikView features the ability to consolidate relevant data from multiple sources into a single application, as well as an associative data model to allow you to explore the data to a way your brain works, state-of-the-art visualizations, dashboard, analysis and reports, and mobile data access. QlikView for Developers Cookbook builds on your initial training and experiences with QlikView to help you become a better developer. This book features plenty of hands-on examples of many challenging functions. Assuming a basic understanding of QlikView development, this book provides a range of step-by-step exercises to teach you different subjects to help build your QlikView developer expertise. From advanced charting and layout to set analysis; from advanced aggregations through to scripting, performance, and security, this book will cover all the areas that you need to know about. The recipes in this book will give you a lot of the information that you need to become an excellent QlikView developer.
Table of Contents (19 chapters)
QlikView for Developers Cookbook
Credits
Foreword
About the Author
About the Reviewers
www.PacktPub.com
Preface
Index

Creating a Moving Range chart


A Moving Range (mR) chart is a way of monitoring variation to try and work out if a system is varying unexpectedly.

The range is simply calculated as the absolute difference between one data point and the previous one. We then calculate an average—usually over a specific subset of the data—of these values and apply a statistical constant (3.267 - D4 anti-biasing constant for a subgroup size of n=2). The great thing about these constants is that you don't need to understand them or how they are calculated; just that they exist.

In this recipe, we are going to use the same set of rainfall data as the previous recipe, Creating a Statistical Control Chart using Standard Deviation, to see how the rainfall data for Heathrow varies over time. We will use a 30-year period as our reference for what "Average" means (the UK Met office uses 1961-1990).

Getting ready

Load the data from the UK Met Office website as outlined in the previous recipe, Creating a statistical control...