Could very old employee stock options still be accessible and viable? My code to make the shapefile available in R is. In this Methods Bites Tutorial, Stefan Jnger (GESIS) and Denis Cohen (MZES) show how to retrieve, manage, and visualize geospatial data in R. After reading this blog post and engaging with the applied exercises, readers will be able to: Note: This blog post builds up on Stefans workshop Management and Analysis of Georeferenced Survey Data in the MZES Social Science Data Lab. The Globalization of Liberalization: Policy Diffusion in the International Political Economy. When and how was it discovered that Jupiter and Saturn are made out of gas? to a shapefile. An alternative to flattening multiple layers onto a two-dimensional map is using a three-dimensional vertical stacking of the layers. You can find an excellent interactive visualization of this issue here. Help me understand the context behind the "It's okay to be white" question in a recent Rasmussen Poll, and what if anything might these results show? Poking around the documentation we see that : st_read typically reads the coordinate reference system as proj4string, but not the EPSG (SRID). The following solution is based on a post by Roger Bivand on R-sig-Geo. Connect and share knowledge within a single location that is structured and easy to search. I will see if I can make it any shorter by using. for st_join: arguments passed on to the join function or to st_intersection when largest is TRUE; for st_filter arguments passed on to the .predicate function, e.g. Toward this end, we use processed data from the 2011 German Census, aggregated at a geospatial raster of 1 sqkm grid cells. How can I merge these two polygons inside the same Formal class SpatiaPolygonsDataFrame? How to perform a vector overlay of two SpatialPolygonsDataFrame objects? The original workshop materials, including slides and scripts, are available from our GitHub. I am not a pro with R nor spatial analysis. Merge We now need to merge the lookup table into our spatial object data frame. join. It works but it does not seem to be the most handy approach. The first general package to provide classes and methods for spatial data types that was developed for R is called sp 1.Development of the sp package began in the early 2000s in an attempt to standardize how spatial data would be treated in R and to allow for better interoperability between different analysis packages that use spatial data. Bringing urban space back in: A multilevel analysis of environmental inequality in Germany. Thus, we can use standard data wrangling techniques in R. For instance, we can simply plot the boundary data using ggplot2s geom_sf(). an aggregate function. I am looking for a way to combine the polygons inside a spatial polygons data frame based on a field in the @data slot: the equivalent of dplyr's "group_by" for spdf's. Zeitschrift fr Soziologie 46 (6), 40219, Jnger, Stefan. Can I use this tire + rim combination : CONTINENTAL GRAND PRIX 5000 (28mm) + GT540 (24mm). If both SpatialPolygonsDataFrames, as I understand, contain the exact same polygons you can do: library (raster) int <- intersect (sp1, sp2) It creates a new SpatialPolygonsDataFrames with the data columns from both inputs and since the polygons overlap complete you'll get the same polygons. r SpatialPolygons -, . The merged dataset now has only two variables the close2raleigh grouping variable, plus the special geometry column. Cham: Springer International Publishing, Rttenauer, Tobias. prepared, or a pattern for st_relate. The function returns a SpatialPolygons object to you with the buffer. Lastly, let us save the reprojected file as PhillyHomicides_aea shapefile, as we will use it later on. If you need to install the sp package - see how to do that here. Ah. In order to determine the polygons we use st_intersects, a geometric binary which returns a vector of logical values, which we we can use for subsetting. 542), We've added a "Necessary cookies only" option to the cookie consent popup. This may improve performance. I guess you'd like to aggregate your census data associated to the shapefile as well, so you'll need an intermediate step. 2019. We can see that the States object is a SpatialPolygonsDataFrame. # 2. Our query is vastly similar to our initial one. However, these objects are deeply nested and thus sometimes difficult to handle. Accordingly, the set of social science applications is diverse, ranging from work in the field of social inequalities (Panzera and Postiglione 2020), environmental justice (Rttenauer 2019), conflict research (Oswald, et al. Units are in map units. Asking for help, clarification, or responding to other answers. asked Jan 2, 2017 at 13:19. spatial, We do this by defining a filter which selects only polygons associated with the city name. Lastly, grid cells can be used to provide spatial summaries of variables such as population density or the proportion of ethnic minority residents in small artifical square areas (e.g., square kilometer grid cells). That workflow looks something like this: We can save our SpatialPolygons object as a shapefile using the raster package. Zensus 2011 - Methoden und Verfahren. We can create two or more polygons into a single SpatialPolygon file as well. So now try again: We have created a sgbp object, which is a Sparse Geomtry Binary Predicate. is there a chinese version of ex. Overlapping polygons (between layers, not within layers) are intersected, other spatial objects are appended. This workflow can take researchers a long way in working with geospatial data and constitutes an important step toward full-blown spatial data analyses. Of course, the main difference is that we now request different features in osmdata::add_osm_feature(). We can use the range() command from the R base package to compare the coordinates before and after reprojection and confirm that we actually have transformed them. Using sf to combine polygons that share borders? is a postdoctoral researcher at GESIS, Leibniz Institute for the Social Sciences, where he provides services in the area of geocoding, georeferencing, and spatial linking. Folding several polygons into one multipolygon and querying it. Geospatial data is georeferenced, meaning that direct spatial identifiers in the form of geo-coordinates can reference any point on earth. To learn more, see our tips on writing great answers. In that case we can use over(). LinearRing divides the sphere into two regions. A basic understanding of dplyr data manipulation is by now common. # make sure we understand this error message: # aggregate(x = ph_homic_sp, by = philly_sp, FUN = length). ymax, ymax, ymin, ymin)) # 2. create a spatial polygon from this crds <-cbind (xx,yy) Pl <-Polygon (crds) . Check out the column names of philly_sf and of ph_edu to determine which one might contain the unique identifier for the join. Log in. How can I merge these two polygons inside the same Formal class SpatiaPolygonsDataFrame? Making statements based on opinion; back them up with references or personal experience. population density, area, etc.) The 3D display allows us not only to present information on both the foreign-born population and the senior population at once, but also to relate the two variables to one another. I always end up with a spatial object that lost the data belonging two both polygons or no union at all. Geospatial data can be big as big data. It only takes a minute to sign up. # Points are classified with the values of the polygons. Options 1: Convert the data.frameback to a SpatialPolygonsDataFrame Options 2: Make use of the existing SpatialPolygonsDataFrame Census data the easy(er) way 1) Set up the packages 2) Get the spatial data (tigris) 3) Get the tabular data (acs) 4) Do the merge (tigris) 5) Make your map (leaflet) Saving your map One issue with the leafletmap 2011. Next, we use st_join to perform a spatial join with the points: Now we can group by a variable that uiquely identifies the census tracts, (we choose GEOID10) and use summarize to count the points for each tract and calculate the homicide rate. Asking for help, clarification, or responding to other answers. The geodetic datum used for measurements on Earth is a sphere. The following example shows how to classify coordinates to polygons using the partition operator. is there a chinese version of ex. Merge a point cloud with a source of spatial data Description Merge a point cloud with a source of spatial data. Learn more about Stack Overflow the company, and our products. We use the st_area function on the geometry column and add the result. To subscribe to this RSS feed, copy and paste this URL into your RSS reader. Often we find that we have lots of spatial polygons that represent the same information. Merge polygon inside SpatialPolygonsDataFrame R, The open-source game engine youve been waiting for: Godot (Ep. Since our earth is three-dimensional and maps are only two-dimensional, projection of points comes with the price of distorting geometries upon display. What does a search warrant actually look like? How is "He who Remains" different from "Kang the Conqueror"? Now let us investigate the object we created. Choosing 2 shoes from 6 pairs of different shoes. Lets imagine that you want to extract values for a particular state - Alaska for example. US State Level Map with ggplot2. # Make a set of coordinates that represent vertices, # with longitude and latitude in the familiar, # This step combines the last two together - making Polygons and then SpatialPolygons, # This looks up the GADM dataset - for the country US and returns. For decades, researchers have considered the role of individuals geo-social context (e.g., neighborhoods) when explaining individual behaviors or attitudes. 2020. Spatial data manipulation in R. Learning Objectives. Creating 100s of polygons by hand is a very daunting task. Next, we create a buffer around the city center point. Upgrade to Microsoft Edge to take advantage of the latest features, security updates, and technical support. For instance, a specific location can be represented by a point using a coordinate pair for the locations longitude and latitude. Thanks for contributing an answer to Stack Overflow! Why there is memory leak in this c++ program and how to solve , given the constraints? / Ported to Hugo By jbub, a red buffer of 50 miles around Raleigh (the state capital). We also assign the output to a new object crime_rate. It contains spatial information about the state boundaries but also additional data like the name and some other things. Was Galileo expecting to see so many stars? Spatial polygons are a set of spatially explicit shapes/polygons that represent a geographic location. Not relevant for RGB colorization. For plotting purposes lets subset out Alaska and Hawaii from the current data. 1.1.1 The sp package. More info about Internet Explorer and Microsoft Edge, The geospatial coordinates are interpreted as represented by the, If input polygon edges are straight cartesian lines, consider using, LinearRingShell is required and defined as a, LinearRingHole is optional and defined as a. LinearRing vertices must be distinct with at least three coordinates. With this information, we create a object that holds the coordinates of the city center. Given a list of SpatialPolygons objects, here's how to construct a spatial polygons data frame with one feature per original SpatialPolygons feature. Now that the rotate_sf() function has been defined, we can use it to produce a figure that shows the information on streets and buildings in the base layer. Well use the rgeos package to do that. Weapon damage assessment, or What hell have I unleashed? Select all census tract polygons that intersect with the center buffer, # philly_sf <- st_read("data/Philly/", quiet = T). We can get the data directly from within R using the getData function available in the raster package. # The attribute "LAKENAME_1" exists in the shapefile. Now you have the polygons with their road names. https://cran.r-project.org/web/packages/sp/vignettes/over.pdf, Join attribute data to a polygon vector file, a CRS object with the new projection definition. Find the Philadelphia city center coordinates. In this case the logical vector is recoded to yes / no string values via ifelse(). In addition, we need to create a sf Point object with the Philadelphia city center coordinates: These coordinates are in the USA Contiguous Albers Equal Area Conic projected CRS and the EPSG code is 102003. How did Dominion legally obtain text messages from Fox News hosts? 3.3, Retracting Acceptance Offer to Graduate School, Torsion-free virtually free-by-cyclic groups. Why do we kill some animals but not others? 2016. 2018). We can get around that by dissolving boundaries based on similar attributes. In fact it is so easy it might seem like magic. Raster data (see the Census example below) is great for areal data that do not differ between each geometry. 2004. They can be managed with database joins, which are implemented by R 's merge function. His methodological interests include quantitative approaches to the analysis of clustered data, measurement models, data visualization, strategies for causal identification, and Bayesian statistics. Well use use some randomly generated XY coordinates. By clicking Accept all cookies, you agree Stack Exchange can store cookies on your device and disclose information in accordance with our Cookie Policy. Each individual Aleutian island will be its own polygon and thus when summarizing data each island will have its own mean. Using the shapefile available here I am trying two merge the polygons of Sudan and South Sudan, so that I get the borders of Sudan in 2010. Egypt seems to be missing in your final map. You can use aggregate() from sp package. In additional processing steps, we extract the polygon data of the administrative boundaries in our boundary box and filter those boundaries which belong to Mannheim (as opposed to neighboring cities and municipalities). Basic Spatial Polygon Analysis in R. A fundamental feature of GIS is the ability to explore relationships between characteristics of areas that overlap in space. as in example? a Raster*, a stars, or a SpatRaster. The correct term to describe the act of joining, combining, uniting or merging (making 1 out of multiple) polygons seems to be either dissolving or aggregating. What is the ideal amount of fat and carbs one should ingest for building muscle? 2017. Applications not only extend to the analysis of classical geographical entities (e.g., policy diffusion across spatially proximate countries) but increasingly also to analyses of micro-level data, including respondent information from georeferenced surveys or user trace data from Tweets. What is the ideal amount of fat and carbs one should ingest for building muscle? To subscribe to this RSS feed, copy and paste this URL into your RSS reader. Reproject a vector file. I am wondering how to join spatial polygons using R code? His research focus lies at the intersection of political preference formation, electoral behavior, and political competition. Statistische mter des Bundes und der Lnder. My code to make the shapefile available in R is. Here are the arguments that it needs: To count homicides per census tract we can use any field from ph_homic_aea for homicide incidents (we chose OBJ_ID) and philly polygons to aggregate on and save the result as ph_hom_count. We use st_transform and assign the result to a new object. 3.1.2 Installing and loading packages. Geographic Information Systems Stack Exchange is a question and answer site for cartographers, geographers and GIS professionals. 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. Also, the border between Sudan and South Sudan is still there. as in example? The difference between SpatialPolygons and SpatialPolygonsDataFrame are the attributes that are associated with the polygons. For example, when considering where to locate a new retail outlet, a business will consider factors like personal income in neighborhoods, auto or pedestrian accessibility, the . To subscribe to this RSS feed, copy and paste this URL into your RSS reader. Are there conventions to indicate a new item in a list? Chapter 2. This data is available from Stefans z11 package. The function tests if two geometries (lets name them spgeom1 and spgeom2) have points in common or not. Connect and share knowledge within a single location that is structured and easy to search. For the next example our goal is to select all Philadelphia census tracts within a range of 2 kilometers from the city center. Urban Studies, 56(12), 25492567. Simple Spatial Join of Point Feature to Polygon Target Feature Not So Simple (Source Files Included). Thanks for contributing an answer to Geographic Information Systems Stack Exchange! as in example? I edited my question in that sense, that I added the solution I have so far. Now that the sp library is loaded we can use the SpatialPolygons() function to create a SpatialPolygons object in R. Here is the general workflow for generating polygons from scratch: Next we use the Polygon function in the sp package to make a polygon from our matrix of vertices, Then we make poly1 into a Polygon class using the Polygons function, Then we can make firstPoly into a SpatialPolygons. Browse other questions tagged, Start here for a quick overview of the site, Detailed answers to any questions you might have, Discuss the workings and policies of this site. However, separating information across numerous plots makes it hard to relate information from different variables to one another. How do I apply a consistent wave pattern along a spiral curve in Geo-Nodes. Let us remove the axes and other unncesssary aspects of the plot to just keep the map alone using various options in theme() layer. Now let's take data attribute columns six to eight ("AREA", "POP1990", "POP1997") and aggregate them according to the above IDs applying function sum. It integrates three of R's most commonly . Single SpatialPolygons* object. Millions of geometries, such as points, are no exception, making working with geospatial data quite demanding. The ISO field is the same for all polygons. Indicates whether the geospatial coordinates are inside a polygon. What are the consequences of overstaying in the Schengen area by 2 hours? In specific, I down. In this blog post, we have outlined core features of Geographic Information Systems and showcased tools for the retrieval, management, and uni-, bi-, and multivariate descriptive visualization of geospatial data in 3D. Finally, reconvert your dataframe back to a SpatialPolygonsDataFrame providing the previously unified shapefile oregon.union and you obtain both generalized polygons and your census data derived from above summarization aggregation step. Sources of spatial data can be a SpatialPolygons*, an sf / sfc , a Raster*, a stars, or a SpatRaster. The use of geospatial data - data that can be mapped using geographic information systems (GIS) - has become increasingly widespread in the social sciences. is a postdoctoral fellow in the Data and Methods Unit at the Mannheim Centre for European Social Research (MZES), University of Mannheim, and one of the organizers of the MZES Social Science Data Lab. The simple map has longitude and lattitude on its axes. See bind if you want to combine polygons without intersection. We will write it out for later. range() returns the min and max value of a vector of numbers. Next, we proceed similarly for data on a various types of buildings (specified per the value argument in osmdata::add_osm_feature()). Does the double-slit experiment in itself imply 'spooky action at a distance'? On the other hand the application of the dplyr verbs to spatial data science workflow is not that well discussed, and in my opinion an interesting simplification in a number of use cases. We use gArea() from the rgeos library. It only takes a minute to sign up. "settled in as a Washingtonian" in Andrew's Brain by E. L. Doctorow. (You may come across alternative suggestions for joins that operate on the data slot @data of the Spatial* object. Browse other questions tagged, Where developers & technologists share private knowledge with coworkers, Reach developers & technologists worldwide, It sounds like you want a dissolve, which is the. 11.9k 23 23 gold badges 37 37 silver badges 72 72 bronze badges. We will use the gIntersects() function from the rgeos package to select all census tract polygons that intersect with the center buffer. The best answers are voted up and rise to the top, Not the answer you're looking for? geo_point_in_polygon(longitude,latitude,polygon). GDAL cannot retrieve SRID (EPSG code) from proj4string strings, and, when needed, it has to be set by the user. Merging Spatial Data Sets Like regular pandas DataFrames, GeoDataFrames can be merged with one another based on common merging variables. Lets make a map using the newly created USborder and the state level data. Let us go back to the "PhillyHomicides" shapefile we exported earlier. The first coordinate must be equal to the last. Acceleration without force in rotational motion? To subscribe to this RSS feed, copy and paste this URL into your RSS reader. Connect and share knowledge within a single location that is structured and easy to search. Now that we have gathered all the data that we would like to include in our illustration, the question is how to best present the different types of geospatial information. Of 50 miles around Raleigh ( the state boundaries but also additional data like the name and other. Not others nor spatial analysis constitutes an important step toward full-blown spatial data, (. Asking for help, clarification, or responding to other answers used for measurements on earth choosing 2 shoes 6! A coordinate pair for the next example our goal is to select all census tract polygons that represent geographic... Sense, that I added the solution I have so far one multipolygon querying... The gIntersects ( ) returns the min and max value of a vector of numbers can see that States... # make sure we understand this error message: # aggregate ( =. You may come across alternative suggestions for joins that merge spatial polygons r on the column! The current data PRIX 5000 ( 28mm ) + GT540 ( 24mm ) we need. A new object crime_rate the center buffer object with the new projection definition damage! Clarification, or responding to other answers thanks for contributing an answer to geographic information Systems Stack Exchange of... Create a object that lost the data slot @ data of the layers summarizing data each island will its. And add the result to a polygon vector file, a CRS object with the new projection.... '' in Andrew 's Brain by E. L. Doctorow answer site for cartographers, geographers GIS! Step toward full-blown spatial data Sets like regular pandas DataFrames, GeoDataFrames can be represented by a point cloud a! Exchange is a sphere back them up with a spatial object data frame creating 100s of polygons by hand a. A question and answer site for cartographers, geographers and GIS professionals 37 silver badges 72 bronze.:Add_Osm_Feature ( ) I have so far polygons by hand is a very daunting.... In Germany or no union at all but not others geometries upon display values of the latest features security... For building muscle will be its own polygon and thus sometimes difficult to handle of spatial that! So far legally obtain text messages from Fox News hosts of spatial polygons are a set of spatially explicit that. Grid cells difference is that we now request different features in osmdata: (! Point on earth for measurements on earth the geospatial coordinates are inside a polygon vector file, a object! Cookie consent popup merge spatial polygons r be accessible and viable data slot @ data of the layers find we... Have points in common or not * object different from `` Kang the ''! 1 sqkm grid cells variables the close2raleigh grouping variable, plus the special geometry column and the. Variable, plus the special geometry column and add the result to polygon. Ingest for building muscle projection of points comes with the values of the layers and. Of philly_sf and of ph_edu to determine which one might contain the unique identifier for next! Apply a consistent wave pattern along a spiral curve in Geo-Nodes Sets like regular DataFrames! Nor spatial analysis, Retracting Acceptance Offer to Graduate School, Torsion-free virtually free-by-cyclic.! Urban space back in: a multilevel analysis of environmental inequality in Germany create a buffer around city. Leak in this c++ program and how to join spatial polygons that represent the same Formal class SpatiaPolygonsDataFrame important toward. Now try again: we can get the data directly from within R using the getData function available in is! Geodetic datum used for measurements on earth accessible and viable simple map longitude... Geospatial coordinates are inside a polygon we kill some animals but not others bringing space! Main difference is that we now request different features in osmdata::add_osm_feature ( ) difference between SpatialPolygons and are! Employee stock options still be accessible and viable this URL into your RSS reader about Overflow. 5000 ( 28mm ) + GT540 ( 24mm ), let us save the reprojected file as PhillyHomicides_aea shapefile as... Acceptance Offer to Graduate School, Torsion-free virtually free-by-cyclic groups data frame so far there is memory leak this! Shapefile using the newly created USborder and the state capital ) 've added a `` Necessary cookies only '' to! I guess you 'd like to aggregate your census data associated to the last take. Of geometries, such as points, are no exception, making working with geospatial data and an... Spatial identifiers in the raster package polygons using the partition operator employee stock still... Perform a vector of numbers PhillyHomicides '' shapefile we exported earlier is georeferenced, meaning direct. Spatial object that holds the coordinates of the spatial * object this issue here,! Form of geo-coordinates can reference any point on earth is three-dimensional and are! Goal is to select all Philadelphia census tracts within a single location that is structured and easy to search,! This RSS feed, copy and paste this URL into your RSS reader # make sure we understand this message... Opinion ; back them up with references or personal experience querying it data each island will be its mean! Comes with the center buffer SpatialPolygonsDataFrame objects making statements based on a post by Bivand... Simple ( source Files Included ) this issue here of philly_sf and of ph_edu determine... Engine youve been waiting for: Godot ( Ep all polygons of a vector numbers., that I added the solution I have so far state - Alaska for example you... You have the polygons with their road names SpatialPolygonsDataFrame R, the main difference is that we lots. Border between Sudan and South Sudan is still there vastly similar to our one! To yes / no string values via ifelse ( ) item in a list Overflow. Multilevel analysis of environmental inequality in Germany am wondering how to do that here making working with geospatial is... Data is georeferenced, meaning that direct spatial identifiers in the International political.... Set of spatially explicit shapes/polygons that represent the same information longitude and.! Via ifelse ( ) returns the min and max value of a vector overlay two! So now try again: we can get around that by dissolving boundaries based on similar attributes to the. The first coordinate must be equal to the cookie consent popup when explaining individual behaviors or attitudes + combination... Discovered that Jupiter and Saturn are made out of gas for building muscle # make sure we understand this message. The values of the latest features, security updates, and technical support and easy search! At all, making working with geospatial data quite demanding a `` cookies... The original workshop materials, including slides and scripts, are available our. Three-Dimensional vertical stacking of the spatial * object still be accessible and viable relate information from merge spatial polygons r variables one! Alaska and Hawaii from the 2011 German census, aggregated at a '. Object data frame was it discovered that Jupiter and Saturn are made out of gas engine youve been waiting:... Responding to other answers subscribe to this RSS feed, copy and paste this into. Fun = length ) difference between SpatialPolygons and SpatialPolygonsDataFrame are the attributes that are associated with price. Inequality in Germany German census, aggregated at a geospatial raster of 1 sqkm grid.! Godot ( Ep the attribute `` LAKENAME_1 '' exists in the Schengen by! To this RSS feed, copy and paste this URL into your RSS reader lattitude on its.... Without intersection on a post by Roger Bivand on R-sig-Geo common merging variables value of a vector overlay two. 6 ), 40219, Jnger, Stefan coordinates to polygons using R code attribute `` LAKENAME_1 '' in. And max value of a vector overlay of two SpatialPolygonsDataFrame objects most handy approach making statements based on attributes! The function returns a SpatialPolygons object as a Washingtonian '' in Andrew 's Brain by L.! Neighborhoods ) when explaining individual behaviors or attitudes your final map `` cookies! The layers latest features, security updates, and technical support = philly_sp FUN... S most commonly belonging two both polygons or no union merge spatial polygons r all different shoes polygons into a single SpatialPolygon as! With a spatial object that lost the data directly from within R using the newly created USborder and state... There conventions to indicate a new item in a list, are available from our GitHub looking for into. The Globalization of Liberalization: Policy Diffusion in the International political Economy there conventions to indicate a item... Operate on the geometry column and add the result to a new object.... Function from the rgeos library open-source game engine youve been waiting for: Godot ( Ep own polygon and sometimes! Technical support about the state capital ) there conventions to indicate a new item in a list missing! Solve, given the constraints so simple ( source Files Included ) interactive... If you want to extract values for a particular state - Alaska for example use... `` Kang the Conqueror '' difference is that we have lots of spatial polygons that represent the Formal. Zeitschrift fr Soziologie 46 ( 6 ), we use gArea ( ) from sp package - see to! For joins that operate on the geometry column they can be represented by a cloud! Perform a vector of numbers and some other things might contain the unique identifier for the locations longitude and on. On earth, 25492567 'spooky action at a geospatial raster of 1 sqkm grid cells later on to! Something like this: we have created a sgbp object, which a. Question and answer site for cartographers, geographers and GIS professionals string values via ifelse ( ) create two more... Object data frame of numbers merge spatial polygons r of geometries, such as points, available! Object as a shapefile using the raster package, which are implemented merge spatial polygons r R & # x27 s... Shapefile using the raster package take advantage of the city center single location is!