Hi,

Sorry this is a long rambly post. In short, I think the help needs a fixed breaks example. I suggest adding it to tm_polygons help - does this make sense, or is there a better place?

I have been trying to create a map with fixed breaks.

This code works:

tm_shape(World) +
  tm_symbols(fill = "well_being", fill.scale = tm_scale(breaks = c(2,4,6,10)))

And if we want to specify colour etc we can pad out to this:

  tm_symbols(fill = "well_being", fill.scale = tm_scale_intervals(values = "brewer.greens", 
    n = 6, 
    style = "fixed",
    breaks = c(2,4,6,10)))

However I think the help needs clarifying.

Under help for tm_scale_intervals is says for style:

Method to create intervals. Options are "cat", "fixed", "sd", "equal", "pretty", "quantile", "kmeans", "hclust", "bclust", "fisher", "jenks", "dpih", "headtails", and "log10_pretty". See the details in classInt::classIntervals() (extra arguments can be passed on via style.args).

Ok, fine.

Here I wasn't paying attending, and looked at classInt::classIntervals() which is not part of tmap, but I didn't realise that at the time.

That uses plot(classIntervals(jenks71$jenks71, n=5, style="fixed", fixedBreaks=c(15.57, 25, 50, 75, 100, 155.30)), pal=pal1, main="Fixed") as a fixed example so I was trying to work with fixedBreaks rather than breaks.

So I think we need a fixed breaks example somewhere. Is in the help under ?tm_polygons the best place? Or somewhere else?

Thanks!
Nick.