To add a column to data.table object, we can follow the below steps −First of all, create a data.table object.Add a column to the object using := functionCreate the data.table objectLet’s create a data.table object as shown below −library(data.table) x

To check if a column is categorical in R data frame, we can follow the below steps −First of all, create a data frame.Use class function to check the class of the column.Create the data frameLet's create a data frame as shown below − Live Demox

To set the nuber of digits to be printed for summary command without using options(digits), we can use digits argument while printing the summary. −Example 1Using mtcars data and finding the summary statistics with number of digits set to 2 − Live Demosummary(mtcars, digits=2)On executing, the above script generates the below ... Read More

To find the number of rows in a data.table where two or more column values meet a criteria, we can follow the below steps −First of all, create a data.table object.Find the number of rows meeting a criteria.Create data.table objectLet’s create a data.table object as shown below −xRead More

To subset a named vector based on names, we can follow the below steps −Create a named vector.Subset the vector using grepl.Create the named vectorLet’s create a name vector as shown below − Live DemoV

To find the number of unique values of multiple categorical columns based on one categorical column, we can follow the below steps −First of all, create a data frameUse summarise_each function with n_distinct function to find the number of unique values based on a categorical column.Create the data frameLet's create ... Read More

To check which element of a list which is a logical list is TRUE, we can follow the below steps −First of all, create a list with logical values.Use which function with unlist function to find the position of TRUE elements.Create the listLet’s create a list as shown below −ListRead More

To display two equal signs using ggplot2, we can follow the below steps −First of all, create a data frame.Create a scatterplot(you can create any other plot).Display two equal signs using annotate functionCreate the data frameLet's create a data frame as shown below − Live Demox

To display regression intercept using model in a plot created by ggplot2, we can follow the below steps −First of all, create the data frame.Use annotate function of ggplot2 to create the scatterplot with regression intercept displayed on the plot.Check the regression intercept.Create the data frameLet's create a data frame ... Read More

To display regression slope using model in a plot created by ggplot2, we can follow the below steps −First of all, create the data frame.Use annotate function of ggplot2 to create the scatterplot with regression slope displayed on the plot.Check the regression slope.Create the data frameLet's create a data frame ... Read More