摘要: but when the document is processed these lines are part of the control commands, and only the lines corresponding to R code will actually be printed in the resulting document. So to explain how to use knitr requires writing lines that look like code but are not executed, or to use some very clever tricks. Gandrud has clearly used the former approach, which has led to the typos. However, the author provides links to the github pages where errors/typos are addressed. If the reader finds a mistake, she can easily check this site to see if it has been reported, and if not, she can submit the error report. As for quality of the book, it covers a lot of good material, but could be improved and made more relevant with additional examples and figures.If this book goes into a second edition, a recommendation is to include more figures! Good graphics are an important part of data analysis and particularly plots made with the ggplot2 …