R programming language provides several libraries that contain pre-existing functions to make programming tasks more efficient. To import a library in R, you can use the library() or require() function. Here are some examples:
# Using library() function
library(dplyr) # loads the dplyr package
library(ggplot2) # loads the ggplot2 package
# Using require() function
require(lubridate) # loads the lubridate package
require(tidyr) # loads the tidyr package
Note that the require() function returns a Boolean value indicating whether the package was successfully loaded (TRUE) or not (FALSE). On the other hand, the library() function does not return a value.
Once the libraries are imported, you can use their functions in your R code. For example:
# Using functions from dplyr package
df <- iris %>%
group_by(Species) %>%
summarize(mean_sepal_length = mean(Sepal.Length),
mean_sepal_width = mean(Sepal.Width))
# Using functions from ggplot2 package
ggplot(df, aes(x = Species, y = mean_sepal_length)) +
geom_bar(stat = "identity", fill = "blue")