Overview, Index, Links#
We utilize the open source freeware R in this course.
When using R, several tasks are used quite often without a detailed explanation given for each use. We therefore have created a reference page for the most common uses. We have several pages in this section that deal with typical issues and the code in R that gets around them.
Index of Appendix Pages#
The following list describes the contents of each page:
Statistical Formulas: Key notation for understanding R commands and statistical models.
Helpful Code: Basic tasks in R like calculating standard descriptives and the 5-Number Summary along with using the cat() function to display text and code output together.
Extracting Columns from Data Frames as Vectors: In a large data set, this single operation is used quite often to grab vectors of data we wish to analyze.
Subsetting a Data Frame: Using the subset() function to extract specific types of data points from a data frame.
Creating a Data Frame: Entering data into R by creatinng vectors using the concatenate function c() and then joining them into a dataframe.
Creating a Grid of Graphics: When displaying multiple graphical objects at once, we can use the layout() and matrix() functions to create a grid. The graphical objects will be reduced in size and laid out as we specify. The result saves space and helps to organize content in a more meaningful way.