Search icon CANCEL
Subscription
0
Cart icon
Your Cart (0 item)
Close icon
You have no products in your basket yet
Save more on your purchases now! discount-offer-chevron-icon
Savings automatically calculated. No voucher code required.
Arrow left icon
Explore Products
Best Sellers
New Releases
Books
Videos
Audiobooks
Learning Hub
Conferences
Free Learning
Arrow right icon
Arrow up icon
GO TO TOP
Simulation for Data Science with R

You're reading from   Simulation for Data Science with R Effective Data-driven Decision Making

Arrow left icon
Product type Paperback
Published in Jun 2016
Publisher Packt
ISBN-13 9781785881169
Length 398 pages
Edition 1st Edition
Languages
Arrow right icon
Author (1):
Arrow left icon
Matthias Templ Matthias Templ
Author Profile Icon Matthias Templ
Matthias Templ
Arrow right icon
View More author details
Toc

Table of Contents (13) Chapters Close

Preface 1. Introduction 2. R and High-Performance Computing FREE CHAPTER 3. The Discrepancy between Pencil-Driven Theory and Data-Driven Computational Solutions 4. Simulation of Random Numbers 5. Monte Carlo Methods for Optimization Problems 6. Probability Theory Shown by Simulation 7. Resampling Methods 8. Applications of Resampling Methods and Monte Carlo Tests 9. The EM Algorithm 10. Simulation with Complex Data 11. System Dynamics and Agent-Based Models Index

Machine numbers and rounding problems

A computer cannot store any value of a continuous distribution exactly, and continuous values get discretized (rounded) on a fine scale. The rounding of values and storage of values as machine numbers should always be kept in mind; for most applications, this doesn't lead to any problems.

"Most" means "not always". Some examples are shown in the following topics that will leave most users without background knowledge in machine numbers perplexed and irritated.

As a motivating example, the following "bug'' report (software R) serves as an example:

From: focus17@libero.it

To: R-bugs@biostat.ku.dk

Subject: error in function trunc

Date: Fri, Jul 2007 15:03:58 +0200 6 (CEST)

The following command will get a wrong result:

trunc (2.3 * 100)
## [1] 229

Answer Duncan Murdoch: That is the correct answer. 2.3 is not representable Exactly; The actual value used is slightly less.

Remark: trunc() is the largest integer...

lock icon The rest of the chapter is locked
Register for a free Packt account to unlock a world of extra content!
A free Packt account unlocks extra newsletters, articles, discounted offers, and much more. Start advancing your knowledge today.
Unlock this book and the full library FREE for 7 days
Get unlimited access to 7000+ expert-authored eBooks and videos courses covering every tech area you can think of
Renews at $19.99/month. Cancel anytime