Machine Learning for Hackers

Errata for Machine Learning for Hackers

Submit your own errata for this product.

The errata list is a list of errors and their corrections that were found after the product was released. If the error was corrected in a later version or reprint the date of the correction will be displayed in the column titled "Date Corrected".

The following errata were submitted by our customers and approved as valid errors by the author or editor.

Color Key: Serious Technical Mistake Minor Technical Mistake Language or formatting error Typo Question Note Update

Version Location Description Submitted By Date Submitted Date Corrected
Page 15
code example

good.rows<-ifelse(nchar(ufo$DateOccurred)>!=8 | nchar(ufo$DateReported)!=8,FALSE, TRUE) This has an errant '>' in the first call to 'nchar'. Removing it, the result of "length(which(!good.rows))" is 731, rather than the printed 371.

Note from the Author or Editor:
It is a typo, thank you for pointing it out. Thankfully, the error does not exist in the supplemental code.

Andrew Broman  Feb 14, 2012 
Page 141
First full paragraph

R-squared should not be defined in terms of RMSE of a model, but in terms of MSE -- as the latter is equivalent to the variance of the distribution when the model is the expected value of the distribution. All references to RMSE in the full paragraphs on this page should be replaced with references to MSE.

John Myles White
John Myles White
Apr 08, 2012