R dplyr::summarise() or summarize() Function

R dplyr summarize() Function

The dplyr summarise()(or summarize()) function aggregates data into a single summary value for each group or the entire dataset if ungrouped.   It collapses multiple rows into a concise statistical summary, such as the mean, sum, and count.  Developers often use summarize() with group_by(), which splits the data into groups based on one or more categorical variables (Columns … Read more

How to Count Unique Values by Group in R

Counting unique observations by single or multiple groups in R

What do you mean by counting unique values by group? Well, it means you divide the dataset into subsets based on the values of one or more categorical variables (columns). Within each subset, you determine the number of distinct (unique) values in a specific column. Here are three ways to count unique values by group: Using … Read more

dplyr group_by(): Grouping Variables in R

The group_by() Function from dplyr package

The group_by() function from the dplyr package allows us to group data frames by one or more variables (columns), enabling subsequent operations to be performed on these groups. For example, calculating the total sales for each category or counting the number of items in each category. You cannot use the group_by() function alone because it … Read more

R dplyr::slice() Function

The dplyr slice() method in R

The dplyr::slice() function subsets rows by their position or index within a data frame. If you want to select specific rows from a data frame, use the slice() function and pass the index of the specific rows, and it will return a data frame containing those rows. In the above figure, we selected rows 3 … Read more

How to Create an Empty Vector and Append Values in R

Creating an Empty Vector and Append Values in R

R vectors are atomic, meaning they contain homogeneous data types. They are contiguous in memory. Here are some of the best approaches for vector initialization and appending values in the future: Using type-specific functions The most efficient and quickest way to create an empty vector is to use type-specific functions like numeric(0), which will return … Read more