From db001dce67d8c8e8b66a3b67b85b3e3726fe904d Mon Sep 17 00:00:00 2001 From: Robin Lovelace Date: Wed, 25 Oct 2017 09:33:31 +0100 Subject: [PATCH] Fix issue, define 'sticky' --- 02-spatial-data.Rmd | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/02-spatial-data.Rmd b/02-spatial-data.Rmd index 6a369d03e..e1c553887 100644 --- a/02-spatial-data.Rmd +++ b/02-spatial-data.Rmd @@ -187,7 +187,7 @@ summary(world["lifeExp"]) ``` Although we have only selected one variable for the `summary` command, it also outputs a report on the geometry such as its `MULTIPOLYGON` geometry type. -This is due to the sticky behavior of the geometry columns of **sf** objects (see Chapter \@ref(attr)). +This demonstrates the 'sticky' behavior of the geometry columns of **sf** objects, meaning the geometry is kept unless the user deliberately removes them, as we'll see in section \@ref(vector-attribute-manipulation). Hence, the result provides a quick summary of both the non-spatial and spatial data contained in `world`: the average life expectancy is 73 years (ranging from less than 50 to more than 80 years) across all countries which are represented in the form of `MULTIPOLYGON` geometries. `MULTIPOLYGON` geometries allow more than one polygon per row (here: country). This representation is necessary for countries with many islands such as Indonesia and Greece.