Make correction to an if statement (checking for NULL value)
Revise 'scale_colour_gradient' parameters in ggplot
Prepend starting coordinates in 'geom_smooth' statement
Change order of arguments in function
Add missing arguments in example provided in help
Change order of @param entry for 'df_folder_path' argument
Correct syntax associated with 'geom_smooth' statement
Update help file for 'hysplit.dispersion.animation'