multiplot: Multiple plot function
In jobonaf/dartle: Air Quality Model Benchmarking

Multiple plot function

1	multiplot(..., plotlist = NULL, cols = 1, layout = NULL)

`...`	ggplot objects to plot
`plotlist`	list of ggplot objects to plot
`cols`	number of columns in layout
`layout`	a matrix specifying the layout. If present, 'cols' is ignored. If the layout is something like `matrix(c(1,2,3,3), nrow=2, byrow=TRUE)`, then plot 1 will go in the upper left, 2 will go in the upper right, and 3 will go all the way across the bottom.