Custom palette in tmap

Unlike ggplot2, where setting a custom color scale happens in a scale_ call, colors in tmap layers are specified in the layer in which they are mapped. For example, take a plot of the age_18_24 variable from prop_by_age:

tm_shape(prop_by_age) +
  tm_raster(col = "age_18_24")

Since color is mapped in the tm_raster() call, the specification of the palette also occurs in this call. You simply specify a vector of colors in the palette argument. This is a another reason it's worth learning ways to generate a vector of colors. While different packages could have very different shortcuts for specifying palettes from color packages, they will generally always have a way to pass in a vector of colors.

Let's use some palettes from the last exercise with this plot.

In the first plot, use the blups palette instead of the default.
In the second plot, use the vir palette instead of the default.
In the third plot, use the rev(mag) palette instead of the default. rev() just reverses the order of a vector, so this uses the same colors but in the opposite order.

Exercise

Custom palette in tmap

Instructions