When data is an atomic vector, it'll be converted to a data frame with
following columns:
.names: the names for the vector (only applicable if names exist).
value: the actual value of the vector.
# S3 method for numeric
fortify_data_frame(data, ...)A data frame.
An object to be converted to a data frame.
Arguments passed to methods.
Other fortify_data_frame methods:
fortify_data_frame.character(),
fortify_data_frame.default(),
fortify_data_frame.matrix()