In this tutorial, we will learn how to split a dataframe into a list of dataframes by groups in R. We will first learn how to use the base R function, split(), to divide a dataframe into multiple dataframes into a list. Then, we will learn how to use dplyr's group_split() … [Read more...] about How to Split a Dataframe into a list of Dataframes by groups in R
How to sum a column by group in R
In this tutorial, we will learn how to compute the sum of a column by groups in another column in a dataframe. Basic, idea is to group the dataframe by the grouping variable/column and then find the sum for each group. Let us get started by loading tidyverse suite of R … [Read more...] about How to sum a column by group in R
How to extract a column of a dataframe as a vector in R
In this tutorial, we will learn how to extract a column from a dataframe in R. We will extract a column as a vector using base R method and then see multiple examples of using dplyr's pull() function to extract a column from a dataframe. Getting Ready with Packages and Data … [Read more...] about How to extract a column of a dataframe as a vector in R
How to number rows within a group in dataframe
In this tutorial, how to add numbers to rows with in each group in a dataframe in R. The picture below illustrates an example of adding row numbers per group. Packages And Data We will first create sample dataframe using tibble function and then use dplyr's functions to add … [Read more...] about How to number rows within a group in dataframe
dplyr count(): count unique values of a variable
In this tutorial, we will learn how to count unique values of a variable(s) or column using dplyr's count() function. dplyr's count() function is a convenient function that combines grouping operation and counting the number of observation in each group. We will learn of 4 … [Read more...] about dplyr count(): count unique values of a variable