How to remove specific features of SpatialPolygonsDataFrame based on attributes in R?

Question

Since it is not appreciated to ask a question under an already existing question which has been answered, here my question linking to this question URL:Simple way to subset SpatialPolygonsDataFrame (i.e. delete polygons) by attribute in R where you can also acquire the dataset.

Does anyone have an idea how to remove multiple features from the SpatialPolygonsDataFrame based on a vector of values?

head(world.map@data)
#   FIPS ISO2 ISO3 UN                NAME   AREA  POP2005 REGION SUBREGION     LON     LAT
# 0   AC   AG  ATG 28 Antigua and Barbuda     44    83039     19        29 -61.783  17.078
# 1   AG   DZ  DZA 12             Algeria 238174 32854159      2        15   2.632  28.163
# 2   AJ   AZ  AZE 31          Azerbaijan   8260  8352021    142       145  47.395  40.430
# 3   AL   AL  ALB  8             Albania   2740  3153731    150        39  20.068  41.143
# 4   AM   AM  ARM 51             Armenia   2820  3017661    142       145  44.563  40.534
# 5   AO   AO  AGO 24              Angola 124670 16095214      2        17  17.544 -12.296

I would like to remove the features which have the NAMES 'Finland', 'Norway', 'Sweden', 'Denmark' (no offense, I just do not have data for Scandinavia ;) ).

Following approaches failed:

world.map <- world.map[world.map@data$NAME != c('Finland', 'Norway', 'Sweden', 'Denmark'), ]
# does not work at all

world.map <- dplyr::filter(world.map@data, NAMEN %in% c('Finland', 'Norway', 'Sweden', 'Denmark'))
# results in a dataframe, spatial information is lost

I would guess that there is an approach using base::which() and %in%, but I do not have any idea how to go on. The answer of @Jeffrey Evans in this post see URL:https://gis.stackexchange.com/questions/57844/subset-a-spatialpolygonsdataframe-by-id-in-r could provide a useful hint...

Answer 1

You may subset the SpatialPolygonsDataFrame by row ids:

# row numbers of countries, exluding scandinavia
ids <- which(
!(world.map$NAME %in% c('Finland', 'Norway', 'Sweden', 'Denmark'))
)

# subset
not_scandinavia <- world.map[ids, ]

# plot
plot(not_scandinavia)