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 −x

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 a data frame as shown below − Live Demox

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 −List

To create violin plot for categories with grey color palette in reverse order using ggplot2, we can follow the below steps −First of all, create a data frame.Then, create the violin plot for categories with color of violins in grey palette.Create the violin plot for categories with color of violins with grey palette in reverse order.Create the data frameLet's create a data frame as shown below − Live DemoGroup

To create boxplot for categories with grey color palette in reverse order using ggplot2, we can follow the below steps −First of all, create a data frame.Then, create the boxplot for categories with color of bars in grey palette.Create the boxplot for categories with color of bars with grey palette in reverse order.Create the data frameLet's create a data frame as shown below − Live DemoGroup

To create line chart for categories with grey color palette using ggplot2, we can follow the below steps −First of all, create a data frame.Then, create the line chart for categories with default color of lines.Create the line chart for categories with color of lines in grey palette.Create the data frameLet's create a data frame as shown below − Live Demox

To divide the row values by row mean in R’s data.table object, we can follow the below steps −First of all, create a data.table object.Then, use apply function to divide the data.table object row values by row mean.Create the data framelibrary(data.table) x

To create boxplot for categories with grey color palette using ggplot2, we can follow the below steps −First of all, create a data frame.Then, create the boxplot for categories with default color of bars.Create the boxplot for categories with color of bars in grey palette.Create the data frameLet's create a data frame as shown below − Live DemoGroup

To create scatterplot for categories with grey color palette using ggplot2, we can follow the below steps −First of all, create a data frame.Then, create the scatterplot for categories with default color of points.Create the scatterplot for categories with color of points in grey palette.Create the data frameLet's create a data frame as shown below − Live Demox