Questions tagged [r]

Statistical computing language and software environment.

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7
votes
2answers
7k views

Converting NZMG (or NZTM) to latitude / longitude for use with R map library

I am a statistician with no background in GIS so apologies for the newbie question. We routinely use R for a range of statistical and graphic analysis and are interested in using its map library to ...
4
votes
1answer
2k views

Performing Random-Forest Classification of 10cm Imagery for species-distribution in R (no point-shapes)? [closed]

I'm trying to classify 10cm-resolution images with the RF-package. I do this to separate some species in the forest, seen on my images. While I was searching for an answer, I found the following ...
21
votes
5answers
14k views

Read a table from an ESRI file geodatabase (.gdb) using R

I am trying to read a table directly from an ESRI file geodatabase into R. An example data file can be downloaded here. The database contains a point feature class (Zone9_2014_01_Broadcast) and two ...
14
votes
2answers
16k views

Converting point data into gridded dataframe for histogram analysis using R?

I am very new at using GIS data and only modestly experienced with R. I've been reading about how to analyze spatial data using the spatial-analyst.net PDF book, so I'm not completely lost, but I ...
14
votes
3answers
28k views

R: How to get latitudes and longitudes from a RasterLayer?

I am an absolute beginner of geographic data, so please, forgive me if the question is not appropriate. I downloaded data from NCDC NARR and managed to load into R using the raster package. I would ...
13
votes
2answers
10k views

Clip Spatial object to bounding box in R

Given a Spatial object in R, how do I clip all of its elements to lie within a bounding box? There are two things I'd like to do (ideally I'd know how to do both, but either is an acceptable solution ...
12
votes
2answers
15k views

writeOGR with a spatialpolygon simplified by gSimplify

I'm using gSimplify (rgeos package) to simplify the geometries of a shapefile. The funcion works good, but now I can't write the output in a new shapefile. I tried some ways: writeOGR(simplyshape, ...
10
votes
2answers
448 views

Cleaning blocks pattern from urban LIDAR (blocks uplifted from streets)

We have a 1-meter LIDAR DEM from a city. A small subset can be downloaded from this link: This screenshot shows raw DEM with gray palette (darker belts are streets, and greyish and whitish ...
9
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1answer
3k views

Difference between gdalwarp and projectRaster

I am trying to project a Raster. In R there is the projectRaster() function to to this (below a fully reproducibly example) : # example Raster require(raster) r <- raster(xmn=-110, xmx=-90, ymn=40,...
9
votes
1answer
5k views

Calculating {minimal} distance between polygons in R

I have calculated the surface area of species distributions (merging polygons from shapefiles), but since this area can be comprised of quite distanced polygons, I would like to calculate some measure ...
8
votes
4answers
18k views

Join CSV file to shapefile

I wanted to join a CSV file to a shapefile. When I identified a field to facilitate the join, e.g., map <- spChFIDs(map, as.character(map$ID)) it returned Error in spChFIDs(SP, x) : lengths ...
5
votes
1answer
4k views

Count overlapping polygons in single shapefile with R

I have a shapefile of species ranges for ~ 346 species. Some species have multiple polygon ranges so there are 1,078 polygons and many polygons are multi-part. It looks something like this: I would ...
2
votes
1answer
3k views

Filling contour levels with grain (texture) using Leaflet

I created a program to draw temperature contour map of France: This is the code: library(ggplot2) library(gstat) library(sp) library(maptools) require(rgeos) library(rgdal) library(foreign) library(...
12
votes
1answer
19k views

Reprojecting raster from lat/lon to UTM in R?

i have to turn it into a UTM in order to make the buffer functional. wets<-readOGR(dsn=".",layer="shapefile") r.raster <- raster() extent(r.raster) <- extent(wets) res(r.raster) <- 100 ...
12
votes
3answers
4k views

Spatio-temporal interpolation in R or ArcGIS?

I'm trying to calculate average rainfall value from a number of points using Inverse Weighted Distance tool in ArcGIS 9.3. My problem is that: each point has it own time series, therefore the ...
10
votes
5answers
9k views

Calculate distance in km to nearest points (given in lat/long) using ArcGIS DEsktop and/or R?

I have two point datasets in ArcGIS, both of which are given in WGS84 lat/lon co-ordinates and the points are spread across the whole world. I would like to find the nearest point in Dataset A to each ...
9
votes
2answers
9k views

Convert several SpatialPointsDataFrames to raster

There are 100 SpatialPointsDataFrames in my Workspace. I loaded them on this way: filenames <- list.files(path="", pattern="XYhectareTravelTimes_ez+.*shp") for(i in ...
13
votes
1answer
12k views

Create polygons of the extent and boundary of a given Raster in R

I want to create two polygons. One is of the rectangular extents of my raster. I know I can obtain the extent of the raster using r <- raster("band5.tif") e <- extent(r) plot(e) gives me this: ...
6
votes
1answer
2k views

Clip raster by raster with data extraction and resolution change

I need to stack multiple maps (tif) together and clip them all according to extent of one small raster map (second raster at the top of picture below). However, the size of pixels in each map is ...
6
votes
3answers
4k views

Extracting values from raster according to Lat and long of values?

having 12 files with 12 hdrs for one year: these files are raster (projected WGS84,lat long): samples = 1440 lines = 720 bands = 1 header offset = 0 ...
6
votes
3answers
2k views

Efficient spatial joining for large dataset in R

I am working with rather large data frames that I often need to do a spatial join on. The fastest way I have come up with so far is this method: library(rgdal) download.file("http://gis.ices.dk/...
4
votes
2answers
3k views

Spatial Join in R

I'm fairly new to using R for spatial work so bear with me. I have found questions similar to this but nothing that answers this question specifically enough for me to implement it. I have point data ...
4
votes
1answer
649 views

Processing large amounts of Rasters in R

I have 6500 processed and clipped rasters that indicate snow levels on a daily basis in the northern hemisphere. I need to create a raster that represents a sum of the snow for the season. The winter ...
3
votes
1answer
2k views

GDAL not available in MODIS R package?

I am trying to analyze the MODIS EVI 250m, 16day dataset. I found the R MODIS package and am following the instructions here: https://conservationecology.wordpress.com/2014/08/11/bulk-downloading-and-...
3
votes
2answers
3k views

Combine multiple partially overlapping rasters into a single raster in R

I have about 1,000 rasters which are around 10km x 10km and partially overlap to cover a whole country. I would like to convert these into a single national raster, and where raster overlap, add the ...
3
votes
1answer
983 views

Removing land area from marine region polygons using R

In my pursuit to merge multiple polygons for the purpose of calculating the surface area of marine species distributions, using shapefiles from Marineregions, I am now trying to remove potential land ...
2
votes
1answer
259 views

Incorporating terrain data to predict canopy cover using randomForest in R? [closed]

I have a 5.8 m resolution satellite image (LISS IV by IRS-P6, in bands 4, 3 and 2) of a densely forested region in the Eastern Himalayas (altitude 700 m to 3200 m). My objective is to predict regions ...
2
votes
1answer
1k views

Splitting strings into new rows, retaining geometry

UPDATED BELOW I have 9 shapefiles, each shapefile has 700,000+ rows and I have roughly 12 attribute fields in each shapefile. There are three attribute fields, common to every shapefile, that I am ...
2
votes
1answer
901 views

Same extent and resolution of rasters, but different number of cells

Based on Unable to writeRaster for signature "rasterPCA", "character", I obtained two rasters that are PC1 and PC2 of a bunch of climatic variables. However, irrespective of having ...
20
votes
4answers
8k views

Crop simple features object in R

Is there a function to crop sf map object, similar to maptools::pruneMap(lines, xlim= c(4, 10), ylim= c(10, 15)) used for SpatialPolygon or SpatialLine? I am considering st_intersection() but there ...
7
votes
1answer
2k views

Difference between raster() and readGDAL()?

I am new in working with rasters and after having trouble working with them i'd like to know the difference between those two import functions. for example i did this library(raster) s<-...
5
votes
4answers
417 views

Create a new GRASS database in R with CRS projection

How to create a new GRASS database in R with CRS projection? I am able to create a new one using the following code but it is not projected require(raster) require(spgrass6) initGRASS("/Applications/...
5
votes
1answer
5k views

GDAL loads in Python, but not IPython (Linux)

I am trying my hardest to utilize the work of the good folks at the GeoDa center, but I cannot seem to get all of the components to load. GDAL, in particular, has been giving me some difficulty. The ...
5
votes
3answers
7k views

Remove NA from Raster Layer

I have a RasterLayer and a SpatialPolygonDataFrame. I used the mask function to create a new RasterLayer. The output is correct but it does include lot's of NA values. Now I want to get rid of ...
5
votes
1answer
2k views

Dissolve only overlapping polygons in R

I have a spatialpolygons-dataframe in R that contains overlapping polygon features. I would like to dissolve only the overlapping features into separate polygon features (one feature per par of ...
5
votes
1answer
995 views

Cross-validation of TPS and kriging outputs from the fields package in R

I am looking for existing package or functions that will allow me to cross-validate multiple outputs of Thin plate spline (TPS) and Kriging from the fields package. Does anyone know of any available ...
5
votes
1answer
1k views

R - multicore approach to extract raster values using spatial points

It might look like this question is duplicated, but I'm asking about data extraction by points, rather than by polygons, and I couldn't find hints about point extraction. Therefore, please bare with ...
4
votes
2answers
6k views

Handling multiple-extent-problem to create raster stack in R?

I am storing ~ 30 raster files in a folder and want to create a raster stack. I know that not all of these rasters have completely the same extent. They do have the same resolution and CRS. Thus I ...
4
votes
1answer
3k views

How to create randomly points within polygons for each row of a dataframe matching a Polygon ID with R

My question is similar to this post, but because there are no "perfect" answer and above all no reproducible example I open this question. I have a "SpatialPolygonsDataFrame" and a data frame. Both ...
4
votes
1answer
219 views

How to use lastrees on a catalog with a function requiring a CHM raster?

I'm still fairly new to using LiDAR data and R, so please let me know if this isn't clear. I am using the lidR package to segment individual trees over a large landscape. I have been using the ...
4
votes
1answer
504 views

raster::rasterize set wrong values with enclosed polygons

Similarly to this post rasterize (R package raster) fail to rasterize island polygons? the rasterize function in the raster package is giving me problems with enclosed polygons. In my case, some ...
3
votes
1answer
3k views

Creating DEM from vector contours using GRASS and R?

I want to convert vector contours to a DEM. From other posts, I wanted to use the Grass r.surf.contours tool. Initially, I converted the vector contour layer to a rasterized contours using the ...
3
votes
5answers
2k views

Find nearest point along polyline using 'sf' package in R

This is a follow-up question related to my earlier post about using the sf package to split polylines using nearby points. I have 450 points with XY coordinates and a large river network (~214,000 ...
3
votes
1answer
227 views

fit two sf polygons seamlessly

Copied from my SO question The problem Suppose we have two shapefiles that should border seamlessly. Only, they don't. Is there a way to force them to stick to one another without gaps? The ...
2
votes
1answer
4k views

Clustering of Spatial Data in R or Python [closed]

I am new to GIS. Problem Domain :- I have a stoppage data of different vehicle i.e. the point where vehicle stopped.There are some specific vehicle which stops at some particular point. So, I am ...
1
vote
2answers
2k views

How can I fix a geoTiff with an incorrect CRS?

Trying to load and plot a raster (it's a DEM) in R, but having problems. Using R I read in a raster file: library(raster) dem <- raster("DEM_Victoria.tif") # >70 MB print(dem) class ...
0
votes
1answer
3k views

r openproj to plot in open street map in a different projection

I am very new to geographic data, so I am sorry for the stupidity of the question. I need to plot some data that are in this projection EUREF_FIN_TM35FIN Projection: Transverse_Mercator ...
0
votes
1answer
2k views

Creating grid polygons from coordinates using R or Python [closed]

I have locational data with north-south and east-west coordinates, with a resolution of 100 meters squares. Each data point's location is somewhere within the 100 meters square which centre is given ...
0
votes
3answers
3k views

hdf files in GDAL throwing an error in R gdalinfo

I am having issues using some modis hdf files in R. Working on Windows 10. I had a previous question where gdal wasn't working but I think I have resolved that. I tested with existing tifs and they ...
9
votes
2answers
5k views

Removing intersect of one polygon from another using R?

I am trying to remove the intersect from Poly2 onto Poly1. Below are the coords of the 2 polygons. > coords1 [,1] [,2] [1,] 992.0161 7462.531 [2,] 950.1962 7413.532 [3,] 902.3632 ...

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