Questions tagged [r]

Statistical computing language and software environment.

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7
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212 views

Accessing watershed boundary for lakes in R

I have had success accessing unique database IDs and polygons for various lakes in the US. I'm now looking to get polygons for the watersheds associated with these lakes, but have stumbled a bit. ...
7
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1answer
2k views

Clipping raster brick object in R

I have MODIS NDVI TIFF files for a year I want to first clip it with a irregular polygon (not by its extent only) of my study area and save it as a multi band raster in TIFF format The TIFF image are ...
7
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810 views

Efficiently calculate distance between raster patch edges

I have a binary raster which I've classified into patches using raster::clump. I now want to efficiently calculate the edge-to-edge, i.e. minimum, pairwise distance between patches. I am currently ...
6
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0answers
221 views

Packing squares polygons in a raster grid

In the green area of the raster I have to fit as many square polygons as possible, of three different sizes: 3x3 cell size 2x2 cell size 1x1 cell size With the fact that the approach should be ...
6
votes
1answer
567 views

Cellular Automata Markov for forecast LULC in R software

I would like to forecast land use changes by implementing the Cellular Automata (CA) Markov Chain models in R software. I have the classified LULC maps from 3 times periods (1992,2003,2014), and also ...
6
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0answers
2k views

How to prevent cross-world lines in ggplot world map?

I'm having issues displaying 'great circles' paths and polygons in ggmap, an extension of ggplot2. Please enter the following code to replicate my issues: https://gist.github.com/Robinlovelace/...
6
votes
1answer
417 views

extract() in R raster package slow with non-native format

I've noticed that running extract takes very different amounts of time depending on whether or not the raster is in memory, on disk in the Native format (.grd), or on disk in another format (e.g., ...
5
votes
1answer
110 views

Calculating accumulated walking pace from starting location outwards using R?

Goal In R, I would like to calculate an accumulated cost surface around a starting location, with the cost representing the time (say, hours) to walk from the location outwards in all directions (say,...
5
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0answers
522 views

Correctly handling climate projection data with R

EDIT: An example setup can be found here: The main file is extract_cordex.R I need to analyze climate data as part of my thesis, however I am not particularly trained in working with climate data and ...
5
votes
1answer
555 views

commuteDistance in gdistance package in R giving error

I am currently trying to run a function that "calculates the expected random-walk commute time between nodes in a graph. It is defined as the effective distance (resistance distance) between the ...
5
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0answers
562 views

How to interpolate within defined boundaries of a deformed mesh using R?

My goal is to create an interpolation map of some output model results that are mapped on a deformed mesh (from a numerical simulation). The model results are in an x-y plane (representing coordinates)...
5
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0answers
479 views

Can extracting raster values work in polygons' CRS without raster resampling?

I am trying to extract raster values using polygon layer with different CRS. Raster is in WGS84 (EPSG:4326) and the polygons in UTM (EPSG:23031). 1. If I want to work in the projection of the ...
5
votes
1answer
192 views

Cokriging: zero distance cross-semivariance in undersampled cases [gstat error]

Trying to cokrige two variables that are not perfectly colocated (one has sparser measurements than the other), I faced an issue that I'll illustrate with the following MRE. With the meuse dataset, ...
4
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0answers
50 views

Implementing PostGIS query using sf in R to make ST_Intersection faster

I'm trying to implement this query that speeds up st_intersections by using faster functions, namely ST_Contains and ST_Within, to do ST_Intersection only where absolutely necessary, from PostGIS to R ...
4
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0answers
54 views

Circular focal means with raster and NAs

I am trying to understand circular focal means using rasters having NA values. I made a couple of scenarios to better understand how to combine weight matrices and functions to summarize values. I am ...
4
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2answers
122 views

Calculate the travel time from locations to the closest N points

I want to calculate the travel time (based on walking time) from locations to the closest N points of another dataset. Then I want to create a hull around those N closest points per location Is this ...
4
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0answers
50 views

Quantifying similarity between two independent areas?

I'm assessing areas for suitability for species relocations, so essentially I'm looking to quantify how similar a possible relocation site is to a source site in several metrics. The species may ...
4
votes
1answer
584 views

Handling raster data in a “rotated pole projection” with R?

My question is about using R to transform raster data from a rotated pole projection to a regular latlon grid - and then plotting it. I am working with data from a numerical weather model, which is ...
4
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0answers
1k views

Fastest way to union a set of polygons in R

I want to find the fastest way to union a set of polygons into one large polygon. Lets first get some data: # Load libraries library('raster') library('geosphere') library('mapview') library(...
4
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0answers
519 views

Determining areas on a Voronoi Diagram around a point

I currently have two data sets concerning the Netherlands, one containing longitudes and latitudes of population cores (Hubs) along with other information, such as average house price, and the other ...
4
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0answers
2k views

Clustering of events within a space-time window (R)

I am relatively new to clustering methods and am trying to determine the best method for clustering (or merely grouping) events that fall within a space-time window using preferably R. My goal is to ...
4
votes
1answer
753 views

Failed to create a raster-brick from a netCDF file (.nc)

I am trying to build a raster-brick from a netCDF file (network Common Data Form) leave this link for more information () but to make a brick (which is part of the package raster) throws me the ...
4
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0answers
969 views

Crop raster based on another raster R

library(raster) How can one clip one raster based on another raster? RasA: class : RasterLayer dimensions : 459, 533, 244647 (nrow, ncol, ncell) resolution : 10000, 10000 (x, y) extent ...
4
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0answers
548 views

Spatial weight matrix with boundary effects in R?

I need some help to finalize code for a spatial weight matrix that uses a nearest neighbor definition within regions, but does not allow neighbors from across a political border. For example, ...
4
votes
0answers
1k views

How to avoid “Unable to compute a transformation between pixel/line”?

I am trying to re-project from Equi-rectangular to the NASA global EASE grid (Equal Area Scalable Earth) grid 1383 586 with a ~25 km cylindrical projection (ESPG=3410). The file is provided as HDF5. ...
4
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0answers
228 views

How to set m parameter of clusterR function in R?

I want to manage a clustered computation on raster and thus use the "clusterR" function in R (package 'raster'). However, there's a tuning m parameter to set, but the only explanation about this ...
4
votes
1answer
388 views

Plotting Bare Soil Line on landsat data in RStudio?

I am using RStudio with landsat package for computing and plotting the Bare Soil Line (BSL) on landsat tif image running on my HP Pavilion i7 laptop. The codes for running the BSL() function is as ...
4
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0answers
1k views

Fortifying re-projected shapefile for ggplot2 in R

I have a shapefile of US county boundaries which I got from the NHGIS. I can load the file using the rgdal package and see information about it: library(rgdal) shp_1860 <- readOGR("shp", "...
3
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0answers
46 views

Rotate coordinates from climatic data in raster format (cordex-EU domain 11) to usual coordinate systems

I am trying to create a dataset that shows future climatic condition in Europe aggregates to NUT2 administration level in R. To do so, i work with cordex data (domain EU 11), that is coming ...
3
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0answers
64 views

Difference in raster pixels between Windows x86 and Windows x64

I have a huge problem and I can not find a reason for it. I have two PCa, one in my house and the other in my workplace. The first one is an old notebook with Windows x86 and the other is Windows x64. ...
3
votes
0answers
39 views

Remediating path that crosses international dateline

I'm trying to plot the paths of multiple ships on a world map using R and a series of Lat/Lon points. All is well until the ship crosses the international dateline (-180/180) when the path jumps ...
3
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0answers
59 views

R raster / rasterize creating GeoTIFF with Null Value “grid lines”

I am attempting the seemingly simple task of converting a .csv with lat, lon and population values into a .tif (raster). Here's my R code: geoName <- read.csv("/pathToData/geoName.csv") ...
3
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0answers
44 views

Standard for publication-ready R-based geographic images?

I've been using the ggmap package to create figures that will go in journal articles for many years. These maps are a little harder to create than Leaflet maps, and as OpenStreetMap and Google have ...
3
votes
2answers
120 views

Can BFAST algorithm be applied to to a whole study area/ ROI?

I am working on identification of breakpoints in Landsat based NDVI time series (1990-2018). I am using The Breaks for Additive Seasonal and Trend (BFAST) algorithm which is a pixel based time series ...
3
votes
1answer
78 views

Multiple conditional statements for raster calculation in R

In the context of a RUSLE erosion modelling I would like to calculate the sum of precipitation at the entry date of phenological phases. Suppose I have 13 grids, one of which is the phenophase entry ...
3
votes
0answers
55 views

Test the relationship between two point patterns

I have two point patterns obtained from medical images. Points are used to represent cell markers. By visualization, the point pattern A is extremely possible to be a subset of point pattern B. So is ...
3
votes
0answers
100 views

Split a tmap legend and display in two locations

I would like to split the legend of a tmap object, so that one of the two elements is in the top left, and one in the top right. I have been through the documentation of tm_legend, but could not find ...
3
votes
0answers
60 views

Create foldable section in QGIS tool using R script

I am developping a GUI tool in QGIS using an R script and I am wondering how to add this kind of foldable section in the graphical interface.
3
votes
1answer
156 views

gIntersection error: linearRing not created

I am trying to do something relatively simple but with large shapefiles. I have a shapefile of protected areas in the USA: and watershed boundaries: I want to calculate the percentage and ...
3
votes
0answers
103 views

Calculate the length of shared boundaries between multiple polygons

I am trying to calculate the length of shared boundaries between multiple polygons in R. Specifically, I would like to calculate the shared boundary length of all the polygons in Census Place GIS data ...
3
votes
0answers
570 views

Selecting and deselecting markers in leaflet under R shiny?

I would like to write a script that selects a marker on the map whenever I click on it and then deselect it when I click/select another marker (that is, so that no more that one marker is selected on ...
3
votes
0answers
544 views

Sentinel 2 preprocessing with R

I need to transform Sentinel 2 L1C imagery to preprocessed Level 2A data. Ideally this should happen in R, as the remaining processing stack is already done in R. Are there ready preprocessing ...
3
votes
0answers
176 views

Difference in area calculation between QGIS and R

I used R to calculate the area of every land polygon of the world (Projection of the source shapefile: WGS84; CRS: EPGS: 4326). To do that, I loaded the required packages ("sp" and "raster") and I ...
3
votes
0answers
243 views

Creating Adjacency Matrix using SpatialLinesDataFrame and SpatialPointsDataFrame in R?

I am trying to create an adjacency matrix of power plants that are connected via power lines. The plant data is point data (~8000 observations) with longitude and latitude measurements. The line data ...
3
votes
0answers
37 views

smearing in Linux, but not in Windows

I must have a Linux library out of wack since the following image has "smears" on the colors. Is there a better term? On my Windows 7 RStudio it works fine. this image is from a Ubuntu 16.04 LTS ...
3
votes
0answers
524 views

Leaflet map in R Markdown - not rendering when placed after other plots

I have an R markdown document using shiny with 6 or 7 plots. They all display until the 7th plot, which is a leaflet map, which doesn't display - when I 'run document' there is a big empty space at ...
3
votes
0answers
318 views

Dealing with duplicate locations kriging - a method for replacing with a single location taking the mean of the duplicates? (R)

I understand that the existence of duplicate points (locations) when Kriging will result in a singular covariance matrix. The only way I've encountered people dealing with this is to keep the first of ...
3
votes
0answers
516 views

Using Random Forest for big data?

I used Random Forest regression for my work, but now I have another problem because I have really big data. I am using a VHR and this is much raster information. My script in R is this: rand.zero <...
3
votes
0answers
810 views

Group and aggregate SpatialPolygonsDataFrame by column in R

I'm working with rgdal, sp, maptools, etc. I have a SpatialPolygonsDataFrame that has each row/Polygons list with only one Polygon. It also has an identifier column which I want to use to group by, ...
3
votes
0answers
75 views

Using euclidian distances as spacing for regular points grid in QGIS?

As a means of checking spatial autocorrelation in the selection of training samples for image classification, I am trying out semivariance analysis. I have managed to generate variograms from image ...

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