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Questions tagged [r]

Statistical computing language and software environment.

13
votes
0answers
364 views

rMaps choropleth with custom json

With R I want to make an animated choropleth map with the rMaps package and a custom map. I tried to follow the example of Diego Valle described here and to use the custom map info for Datamaps. ...
9
votes
0answers
701 views

Why does @data@values slot for RasterLayer only contain logical(0) and not the actual values?

Trying to get to the bottom of why, when I read in a raster of NDVI, the @data@values slot does not contain the actual values until I set them manually. For example: NDVI <- raster("./filename....
6
votes
0answers
656 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 ...
5
votes
0answers
216 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
0answers
169 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 ...
5
votes
0answers
388 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 ...
5
votes
0answers
465 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
votes
0answers
1k 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/...
4
votes
0answers
149 views

Polygon and raster in the same plot do not align

I can't manage to plot a raster and boundary of country (sp data frame) in the same plot. The data (lon,lat,value) are in mat data frame. The grid is not regular and comes from a climate change ncdf ...
4
votes
0answers
1k 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
0answers
270 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., ...
4
votes
0answers
1k 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 ...
4
votes
0answers
713 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
votes
0answers
434 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
958 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
votes
0answers
667 views

Subset two rasters with different extent and origin (and resolution) only where there are data in both in R

in R, I have two rasters with different extents and origins (and possibly even resolution). How to efficiently take the subset of each of them only where there are data in both of them? Here is a ...
4
votes
0answers
180 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
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", "...
4
votes
0answers
356 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 ...
3
votes
0answers
100 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
65 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,...
3
votes
0answers
414 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(...
3
votes
0answers
34 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
374 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 ...
3
votes
0answers
331 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
148 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
454 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
2k views

Error in compareRaster(c(x, rasters)) : different extent

I have a RasterStack that I want to add two rasters to. I am using this code library(rgdal) library(raster) #original rasterstack rasterfiles <- list.files("C:\\path_to_rasters", "*.tif$", ...
3
votes
0answers
72 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 ...
3
votes
0answers
582 views

R: Error when stacking multiple raster files

I have a large number of rasters in grid format ("asc"). I created a list of files: files <- list.files("D:/......../EnvironData", pattern='asc', full.names = TRUE) Then I ...
3
votes
0answers
594 views

Create a new NetCDF file combining information from two other NetCDF files in R

I wish to combine the "t" variable from the second .nc file, and use the lat, lon variables from the first .nc file as the lat and lon of the t variable, and store them to a new .nc file, that will ...
3
votes
0answers
936 views

How to use WMS in R?

I like to implement a special WMS-layer with leaflet() in R. But I have no success with the WMS-layer I like to use. library("leaflet") library("sp") # this example from the tutorial works leaflet() ...
3
votes
0answers
366 views

ogr2ogr{gdalUtils} correct syntax to set Ground Control Points for vector georeferencing

I would like to know correct syntax of R {gdalUtils} package (version 2.0.1.7) to georeference Shapefiles using corner points as GCPs. (These Shapefiles have y=height and x=width information, without ...
3
votes
0answers
73 views

Data structure for analysis of relationship between rainfall and vegetation indices?

I have several hundred raster files (NDVI) of the same area dating back to the 1980’s, as well as daily rainfall observations from a nearby weather-station over the same period. The raster files are ...
3
votes
0answers
526 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 ...
3
votes
0answers
240 views

Keys for merging US state/county ANSI's with GADM Unique identifiers?

I've got county-level data from USDA NASS, and I want to merge it with gridded climate data. A preliminary step is the associate the counties with the coordinates of their centroids. If I merge by ...
3
votes
0answers
377 views

Doing spatial regression using big data when Spatial weight matrix is too large for R?

I am currently doing an analysis on a quite huge data set - 250,000 polygons. I have figured out the general Moran's I for a linear model, but when I was trying to do a spatial lag or spatial error ...
3
votes
0answers
773 views

How to Construct Spatio Temporal Clusters of Time Series Data in R

I have count data of one disease for various districts of a state of India on monthly basis. Is it possible to draw spatio temporal clusters in R? I have checked some R- packages for example ...
3
votes
0answers
334 views

Interpreting Global Moran's I and should I krig?

I am trying to weigh up if kriging (or cokriging) the residual error from my model is a valid approach. My first step was to compute whether the error is spatially autocorrelated. I have done this ...
3
votes
0answers
294 views

How to run GAM with raster package?

When I am using the raster package to predict a surface probability map of species distribution using the following functions in R, the following error occurrs: CA132122200=raster("F:/CBG maps-UnProj/...
3
votes
0answers
460 views

How to calculate 90% confidence interval in a raster stack

I have a stack of grid files (23) in ASC format from a MODIS sensor and I need to calculate a 90% confidence interval, mean, min, etc, for each one in R, how can I do that? specially the interval. #...
3
votes
0answers
323 views

R: Can raster predict function pass to predict.rfsrc (a prediction function in a parallel verion of RandomForest)?

It seems that raster predict function can pass to predict.randomForest by setting the "type='response'". I am using a parallel version of randomForest package called the "randomForestSRC" and I am ...
3
votes
0answers
227 views

R - how to create a pre-determined number of identical square polygons to use for a choropleth map?

I am trying to plot crime data density (again!) over a city map, say of NY. As a well known problem there are plenty of examples on this (http://www.obscureanalytics.com/2012/12/07/visualizing-...
3
votes
0answers
774 views

Decision tree classification of satellite image in R

I want to classify satellite image in R using RWeka classifier, J48. I have a CSV file with the classes required, and raster data loaded in R. I am able to make the tree, however, I am not able to use ...
3
votes
0answers
619 views

python equivalent of spatstat's spatial point process functions

Is there a free python package (i.e. PySAL?) that implements the standard summary statistics for spatial point processes, e.g. the F, G, J, and K functions? I'm happy to use R (i.e. spatstat) if ...
3
votes
0answers
394 views

How do I access layer attributes from within QGIS' manageR plugin?

This is probably a fairly basic question, but searches for manageR come up with a lot of noise, and there's no manageR tag. What I'd like to do is load the attributes from a particular field of a ...
2
votes
0answers
22 views

Detecting QGIS file lock

I tried using rgdal::writeOGR in R to overwrite a SHP file that was open in QGIS. Error in writeOGR(x, "C:/myFiles", "testFile", : Creation of output file failed Not only did it fail to ...
2
votes
0answers
15 views

Removing a 'non-gap' gap from a polygon that straddles +/- 180 longitude; looking for an R-based, code solution

I am working with a set of polygons from here: http://lme.edc.uri.edu/index.php/digital-data. In the artic, there are several polygons that straddle the +/- 180 longitude line. These are single ...
2
votes
0answers
29 views

How do I load these 11 images into a multi-band raster in R?

I have a landsat image with 11 bands. I need to run k means classification in R. But i do not need the whole of the image as my study area is much smaller. So I have created shape file of the Region ...
2
votes
0answers
36 views

Generating flow path using r.drain from rgrass

I need to generate the flow path using r.drain from the rgrass7 package in RStudio. I am new to GRASS GIS and prefer to use the R package instead. I want to generate a flow path from a grid cell. ...