Merge polygon inside SpatialPolygonsDataFrame R

Question

I have a Formal class SpatiaPolygonsDataFrame that has two polygons inside it, meaning that when I write length(x@polygons) it gives me answer = 2.

How can I merge these two polygons inside the same Formal class SpatiaPolygonsDataFrame?

Answer 1

You can use aggregate() from sp package. dissolve=TRUE argument will merge your polygons:

> shape
class       : SpatialPolygonsDataFrame 
features    : 2 
extent      : -7.488767, -7.48873, -4.345411e-06, 1.463535e-05  (xmin, xmax, ymin, ymax)
coord. ref. : +proj=longlat +datum=WGS84 +no_defs +ellps=WGS84 +towgs84=0,0,0 
variables   : 1
names       : id 
min values  :  1 
max values  :  2 

> length(shape@polygons)
[1] 2

> shape2 <- aggregate(shape,dissolve=T)

> length(shape2@polygons)
[1] 1

> plot(shape)