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Questions tagged [sp]

An R package for spatial data. Questions on spatial data might be better asked on https://gis.stackexchange.com

615 questions
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Efficient extraction of all sub-polygons generated by self-intersecting features in a MultiPolygon

Starting from a shapefile containing a fairly large number (about 20000) of potentially partially-overlapping polygons, I'd need to extract all the sub-polygons originated by intersecting their different "boundaries". In practice, starting from…
lbusett
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R - convert SpatialLines into raster

In R, we can take a raster and turn it into a SpatialLinesDataFrame with the function rasterToCountour: library(raster) f <- system.file("external/test.grd", package="raster") r <- raster(f) x <- rasterToContour(r) class(x) [1]…
Rich Pauloo
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SpatialPoints and SpatialPointsDataframe

Working with the sp package in R. I wonder when I would use SpatialPoints and when SpatialPointsDataframe. It seems so me that there is not much difference?! Is the only difference that in a SpatialPointsDataframe I can store more attributes?! If…
Stophface
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Create SpatialPointsDataframe

I have a dataframe df1 with 10 columns. Two of these columns are lng and lat. I want to create a SpatialPointsDataframe from df1. When I read on how to create a SpatialPointsDataframe it feels like I have to create a matrix m1 from my two…
Stophface
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How do I generate a Hexagonal grid in R

I would like to be able to create a SpatialPolygons object (which is a Hexagonal grid) that covers another SpatialPolygon. I would like all the Hexagons to have a diameter of 1km (ideally i can vary this) and for all the hexagons together to cover…
h.l.m
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SpatialPolygons - Creating a set of polygons in R from coordinates

I am trying to take create a set of polygons from vertex locations, saved in X,Y format. Here is an example of my data - each row represents the vertices for one polygon. the polygons are squares square <- rbind(c(255842.4, 4111578, 255862.4,…
Leah Wasser
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Converting a "map" object to a "SpatialPolygon" object

I am guessing there is a simple solution to the problem I have been having, but I am having some trouble. I am trying to convert the following map object: require(maps) usa <- map("state") into a SpatialPolygon object using the map2SpatialPolygons…
Mike.Gahan
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Changing the Projection of Shapefile

I am trying to change or assign the projection of a Germany-Shapefile from NA to +proj=longlat +datum=WGS84 +no_defs +ellps=WGS84 +towgs84=0,0,0, but somehow it doesn't work well. Reproducible Example: Shapefile and other files can be downloaded…
And_R
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How to efficiently calculate distance between pair of coordinates using data.table :=

I want to find the most efficient (fastest) method to calculate the distances between pairs of lat long coordinates. A not so efficient solution has been presented (here) using sapply and spDistsN1{sp}. I believe this could be made much faster if…
rafa.pereira
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Creating a regular polygon grid over a spatial extent, rotated by a given angle

Hi all, I am struggling with this and hope someone could come out with a simple solution. My objective is to create a regular polygon grid over the extent of a polygon, but rotated by a user-defined angle. I know that I can easily create a…
lbusett
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3 answers

R Overlay points and polygons with a certain degree of tolerance

Using R, I would like to overlay some spatial points and polygons in order to assign to the points some attributes of the geographic regions I have taken into consideration. What I usually do is to use the command over of the sppackage. My problems…
Nemesi
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How to find which polygon a point belong to via sf

I have a sf object that contains polygon information (precincts) for a metro area, obtained through a .shp file. For a given lat/lon pair, I want to determine which precinct it belongs to. I'm thinking I can utilize sf::st_contains() but am having…
kevinykuo
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Merge data frame with SpatialPolygonsDataFrame

I want to merge a SpatialPolygonsDataFrame : # From https://www.census.gov/geo/maps-data/data/cbf/cbf_state.html states <- readOGR(dsn = "./cb_2014_us_state_20m.shp", layer = "cb_2014_us_state_20m", verbose = FALSE) with a normal…
Ignacio
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PROJ4 to PROJ6 upgrade and "Discarded datum" warnings

Context My questions are related to the changes induced by the upgrade from PROJ4 to PROJ6 and the consequences in various R spatial packages (sp, sf, raster). We receive now a lot of warnings about “Discarded datum” that looks a bit worrying and…
Gilles
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R measuring distance from a coastline

I have a set of coordinates: d1 <- data_frame( title = c("base1", "base2", "base3", "base4"), lat = c(57.3, 58.8, 47.2, 57.8, 65.4, 56.7, 53.3), long = c(0.4, 3.4, 3.5, 1.2, 1.5, 2.6, 2.7)) I would like to know whether the coordinates fall on land,…
Mrmoleje
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