Marcelo questions

Marcelo answers

• lapply with two column arguments
• R Markdown Add Tag to Head of HTML Output
• Show only high density areas with ggplot2's stat_density_2d
• geom_area fill with different colors
• Remove duplicated labels in legend of ggplot
• reg.finalizer() in an R package does not execute at the end of an R session
• Reverse datetime (POSIXct data) axis in ggplot
• Scatterplot: Error in FUN(X[[i]], ...) : object 'Group' not found