Simplify shape
Simplify a shape consisting of polygons or lines. This can be useful for shapes that are too detailed for visualization, especially along natural borders such as coastlines and rivers. The number of coordinates is reduced.
simplify_shape(shp, fact = 0.1, keep.units = FALSE, keep.subunits = FALSE, ...)
shp |
|
fact |
simplification factor, number between 0 and 1 (default is 0.1) |
keep.units |
prevent small polygon features from disappearing at high simplification (default FALSE) |
keep.subunits |
should multipart polygons be converted to singlepart polygons? This prevents small shapes from disappearing during simplification if keep.units = TRUE. Default FALSE |
... |
other arguments passed on to the underlying function |
This function is a wrapper of ms_simplify. In addition, the data is preserved. Also sf objects are supported.
sf object
## Not run:
if (require(tmap)) {
data(World)
# show different simplification factors
tm1 <- qtm(World %>% simplify_shape(fact = 0.05), title="Simplify 0.05")
tm2 <- qtm(World %>% simplify_shape(fact = 0.1), title="Simplify 0.1")
tm3 <- qtm(World %>% simplify_shape(fact = 0.2), title="Simplify 0.2")
tm4 <- qtm(World %>% simplify_shape(fact = 0.5), title="Simplify 0.5")
tmap_arrange(tm1, tm2, tm3, tm4)
# show different options for keeping smaller (sub)units
tm5 <- qtm(World %>% simplify_shape(keep.units = TRUE, keep.subunits = TRUE),
title="Keep units and subunits")
tm6 <- qtm(World %>% simplify_shape(keep.units = TRUE, keep.subunits = FALSE),
title="Keep units, ignore small subunits")
tm7 <- qtm(World %>% simplify_shape(keep.units = FALSE),
title="Ignore small units and subunits")
tmap_arrange(tm5, tm6, tm7)
}
## End(Not run)Please choose more modern alternatives, such as Google Chrome or Mozilla Firefox.