This worksheet goes back to the roots of this course and trains your skills in subsetting data frames. Subsetting summarizes the extraction of individual regions of a data frame (e.g. rows, columns, cells which values fulfill a certain logical expression etc.). After completing this worksheet you should know how to subset data frames using logical expressions.

• R — the interpreter can be installed on any operation system. For Linux, you should use the r-cran packages supplied for your Linux distribution. If you use Ubuntu, this is one of many starting points. If you use windows, you could install R from the official CRAN web page.

• R Studio — we recommend to use R Studio for (interactive) programming with R. You can download R Studio from the official web page.

• your script from W02-1: Reading CSV files

First things first: the following analysis is build on top of your script from W02-1. Please copy your script “W02-1.R”, rename the copy to “W12-1.R” and use it for the programming tasks of this worksheet.

Please create subsets with the following attributes:

• Rows with a coverage of more than 50%. Use squared brackets for a subset.
• Rows with more natural species than agricultural.
• Rows with exactly 3 natural species or 3 agricultural species.
• Rows with a coverage less than 5% and elevation under 1800m.
• Rows where animals where recorded.