R Notebook

library(tmap)
data(World)

tm_shape(World) +
  tm_polygons(
    fill = "#ffce00",  # fill color
    col = "black",     # line color
    lwd = 0.5,         # line width
    lty = "dashed"     # line type
  )

## [tip] Consider a suitable map projection, e.g. by adding `+ tm_crs("auto")`.
## This message is displayed once per session.

tm_shape(World)+ 
  tm_polygons(fill = "grey90") +   # constant fill color 
  tm_symbols(size = "pop_est",     # data variable, mapped to symbol size
             fill = "well_being",  # data variable, mapped to symbol fill color
             shape = "income_grp") # data variable, mapped to symbol shape

tm_shape(World)+
tm_polygons(fill = "HPI")

tm_shape(World)+ tm_polygons(
  fill = "HPI",
  fill.scale = tm_scale_intervals(
    style = "fisher",      # a method to specify the classes
    n = 7,                 # number of classes
    midpoint = 38,         # data value mapped to the middle palette color
    values = "pu_gn_div"   # color palette; 
                           # run cols4all::c4a_gui() to explore color palettes
  ))

tm_shape(World)+ tm_polygons(
  fill = "HPI",
  fill.scale = tm_scale_intervals(
   n = 6, # for n classes 
    style = "fixed",    
    breaks = c(0,10,20,30,40,50,60), # you need n+1 number of breaks
    values = "pu_gn_div"
  ))

tm_shape(World) +
  tm_polygons(
    fill = "HPI",
    fill.scale = tm_scale_intervals(
      breaks = c(0, 10, 20, 30, 40, 50, 60),
      values = "pu_gn_div",
      labels = c("0–10", "10–20", "20–30", "30–40", "40–50", "50–60")
    )
  )