plot_methbars: Projection bars grouped by method
In jonasbhend/NRMgraphics: Graphics and analysis for the NRM projections project

Plots grouped bars (by method) with alternating colours

plot_methbars(meanchange, allchange = NULL, x = NULL, ylim = NULL,
  add.legend = FALSE, yside = 2, add.rect = TRUE, ylab = "", las = 2,
  xlas = 2, title = "", lwd = 10, lwd2 = 2, cex = par("cex.axis"),
  legend.pos = "topright", add = FALSE, colval = 0, coli = NULL,
  axes = TRUE)

`meanchange`	list of projected n-year mean change (method; scenario)
`allchange`	list of projected annual changes (method; scenario)
`x`	named vector with x intersects
`ylim`	vertical extent of plot
`add.legend`	logical, should legend be added?
`yside`	side at which y-axis is labelled (2,4)
`add.rect`	logical, should negative values have grey background shading?
`ylab`	vertical axis labelling
`las,xlas`	orientation o y and x axis labelling
`title`	title for the plot
`lwd,lwd2`	line width of bars and bar extensions
`cex`	character expansion for text
`legend.pos`	placement of legend (see `legend`)
`add`	logical, should plot be added to existing plot?
`colval`	hue(s) for colours in barplot
`coli`	index for dark or light shading of bars (alternating is default)
`axes`	logical, should axes be plotted?