A package that uses Raster objects
You saw the tmap
package makes visualizing spatial classes in sp
easy. The good news is that it works with the raster
classes too! You simply pass your Raster___
object as the shp
argument to the tm_shape()
function, and then add a tm_raster()
layer like this:
tm_shape(raster_object) +
tm_raster()
When working with a RasterStack
or a RasterBrick
object, such as the pop_by_age
object you created in the last exercise, you can display one of its layers using the col
(short for "color") argument in tm_raster()
, surrounding the layer name in quotes.
You'll work with tmap
throughout the course, but we also want to show you another package, rasterVis
, also designed specifically for visualizing raster
objects. There are a few different functions you can use in rasterVis
to make plots, but let's just try one of them for now: levelplot()
.
This exercise is part of the course
Visualizing Geospatial Data in R
Exercise instructions
- Use
tmap
to plot thepop
object, by specifyingpop
as theshp
argument totm_shape()
and adding atm_raster()
layer. - Use
tmap
to plot theunder_1
layer ofpop_by_age
, aRasterStack
object. - Call the
rasterVis
functionlevelplot()
onpop
.
Hands-on interactive exercise
Have a go at this exercise by completing this sample code.
library(tmap)
# Specify pop as the shp and add a tm_raster() layer
tm_shape(___) +
___
# Plot the under_1 layer in pop_by_age
library(rasterVis)
# Call levelplot() on pop