DE-9IM plot tweak, fix #717

04-spatial-operations.Rmd

@@ -347,7 +347,7 @@ text(x = c(-0.5, 1.5), y = 1, labels = c("x", "y")) # add text
 To demonstrate how DE-9IM strings work, let's take a look at the various ways that the first geometry pair in Figure \@ref(fig:relations) relate.
 Figure \@ref(fig:de9imgg) illustrates the 9 intersection model (9IM) which shows the intersections between every combination of each object's interior, boundary and exterior: when each component of the first object `x` is arranged as columns and each component of `y` is arranged as rows, a facetted graphic is created with the intersections between each element highlighted.
 
-```{r de9imgg, echo=FALSE, warning=FALSE, fig.cap="Illustration of how the Dimensionally Extended 9 Intersection Model (DE-9IM) works." }
+```{r de9imgg, echo=FALSE, warning=FALSE, fig.cap="Illustration of how the Dimensionally Extended 9 Intersection Model (DE-9IM) works. Colors not in the legend represent the overlap between different components. The thick lines highlight 2 dimensional intesections, e.g. between the boundary of object x and the interior of object y, shown in the middle top facet." }
 p1_2 = st_as_sf(c(p1, p3))
 ii = st_as_sf(st_intersection(p1, p3))
 ii$Object = "Intersection"
@@ -356,7 +356,7 @@ ii$domain_b = "Interior"
 
 bi = st_sf(x = st_intersection(
   st_cast(p1, "LINESTRING"),
-  st_difference(p3, st_buffer(st_cast(p3, "LINESTRING"), dist = 0.005))
+  st_difference(p3, st_buffer(st_cast(p3, "LINESTRING"), dist = 0.01))
   ))
 bi = st_buffer(bi, dist = 0.01)
 bi$Object = "Intersection"