suppressPackageStartupMessages(library(BoutrosLab.plotting.general))

colourkey.labels <- sapply(
    X = seq(0, 6, 2),
    FUN = function(x) {
        return(as.expression(bquote('10'^-.(as.character(x)))));
        }
    );

legend <- legend.grob(
    legends = list(
        legend = list(
            title = expression(bold(underline('q-value'))),
            continuous = TRUE,
            colours = c('white', 'black'),
            total.colours = 100,
            labels = colourkey.labels,
            cex = 1.3, # label text size
            at = seq(0, 100, length.out = length(colourkey.labels)),
            height = 8
            )
        ),
    label.cex = 1.3,
    title.cex = 1.7,
    title.just = 'left',
    title.fontface = 'bold',
    );

create.scatterplot(
    formula = mpg ~ hp,
    data = mtcars,
    legend =  list( 
        right = list( 
            fun = legend 
            )
        )
    );