All Questions
1,780 questions
10
votes
1
answer
3k
views
Limiting memory that raster package uses in R?
What's the easiest way to limit the memory the raster package uses in R to 5GB of RAM?
Ideally I want any raster that exceeds this size to be written to the hard drive and analysed from a temporary ...
- 1,678
10
votes
1
answer
11k
views
How to assign colors to specific raster values using R
I am using the levelplot function of the awesome rasterVis package to create a map whose values diverge around zero. I am plotting a raster file using a red to blue palette, but I am trying to assign ...
- 616
10
votes
2
answers
5k
views
How to rasterize SpatialPolygons in R?
I'm trying to extract the bathymetry values of my area of interest from a world bathymetry raster layer using the 'rasterize' function in the {sp} package.
*Edits: I found the 'extract' function which ...
- 489
9
votes
3
answers
6k
views
How parallelize the extract function for raster files in R?
I´m trying to parallelize a simple "extract" operation like this:
UseCores<-detectCores() -1
cl<- makeCluster(UseCores)
registerDoParallel(cl)
all.test.poly_period.test<-extract(stack.ts, ...
- 419
9
votes
3
answers
7k
views
Efficiently reading and reclassifying many rasters in R?
I've been tasked to create a suitability analysis of wave conditions in the Gulf of Mexico. I have 2 thousand or so raster files that are about 8 MB each (2438 columns, 1749 rows, 1km cell size). ...
- 91
9
votes
3
answers
7k
views
Per-pixel (statistical) calculations on a raster stack using GDAL
In R, it's relatively trivial to perform per pixel calculations based on a raster stack (e.g., get std.dev for each pixel on a 12 layer GeoTIFF). Unfortunately, the speed is less than desirable when ...
- 257
9
votes
2
answers
6k
views
Re-projecting raster in R: gives warning that projected point(s) not finite?
1. Question
I have encountered a warning using the projectRaster() function in the raster package in R. A full reproducible example is pasted below.
Warning message:
In rgdal::rawTransform(...
- 143
9
votes
4
answers
9k
views
Getting count of non-NA raster cells within polygon using R
I've been running into all sorts of issues using ArcGIS ZonalStats and thought R could be a great way. I'm fairly new to R but I have a coding background.
The situation is that I have several rasters ...
- 257
9
votes
3
answers
6k
views
Using sampleRandom() from large raster without NA values in R?
I have a number of vary large rasters which need to be randomly sampled with the return value being a matrix of x, y, and value. The raster package sampleRandom(raster,n, na.rm=TRUE, xy=TRUE) will do ...
- 471
9
votes
2
answers
2k
views
How to create a solar intensity map for a garden plot?
I'm interested in creating a raster surface that depicts the average solar intensity per unit area for a small garden plot. I imagine the inputs into the model would be the following:
Plot area--for ...
- 51.8k
9
votes
1
answer
3k
views
Understanding the values from transition layers produced by the R package `gdistance`
Background and Aim
I would like to create a cumulative raster representing walking time across a surface.
For my purposes, the cost to be accumulated has to be the walking time as influenced by ...
- 1,546
9
votes
1
answer
10k
views
Spearman correlation between two rasters in R [closed]
I have two rasters of the same area. The only difference is that they were created using two different methods. I would like to compare them and see how correlated they are pixel by pixel.
Any ideas ...
- 111
9
votes
1
answer
592
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 ...
- 91
9
votes
1
answer
3k
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 ...
- 345
8
votes
3
answers
20k
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 ...
- 887
8
votes
3
answers
21k
views
Function (sample code) to extract raster value per polygon in R
I have a raster image (Sentinel-2 band 4) and a shapefile covering the same area than the image (same projection and extension). The shapefile has different polygons which are agricultural fields.
I ...
- 1,138
8
votes
2
answers
4k
views
Sum rasters with different extent in R
I need to sum several rasters (.tiff) with different extent but the same resolution in R.
How can I do it?
- 123
8
votes
1
answer
12k
views
Plotting map resulted from kriging in R
I want to plot a map weighted by prices. I got a data frame of latitudes, longitudes and prices:
> str(data)
'data.frame': 1253 obs. of 3 variables:
$ lon : num 11.2 11.1 11 11 11.3 ...
$ ...
8
votes
3
answers
14k
views
Stack rasters with different origin, dimensions and resolution in R
I have three raster files with the same extent and CRS, but with different origin, dimensions and resolution.
r1
class : RasterLayer
dimensions : 3020, 3043, 9189860 (nrow, ncol, ncell)
...
- 83
8
votes
2
answers
19k
views
How are kappa and overall accuracy related with respect to thematic raster data?
I recently calculated kappa (using confusionMatrix{caret} in R) between a thematic raster dataset at 1m spatial resolution and another at 30m spatial resolution. I was interested in quantifying the ...
- 51.8k
8
votes
1
answer
12k
views
Saving (converting) raster objects in R?
I want to save my raster plot that produced with R to ArcGIS raster (.img, .tif and ASCII) file.
- 93
8
votes
5
answers
10k
views
In R, set NA cells in one raster where another raster has values
I have two rasters in R. I want to set values to NA in the first raster where the second raster has values. I think this should be simple, using the raster package, with two RasterLayer objects ...
- 670
8
votes
1
answer
14k
views
Plotting a raster stack with ggplot2
My aim is to plot a rasterstack as a single image using ggplot2. First, I apply ggplot on a single layer raster using the following code:
#Load packages
library(raster)
library(ggplot2)
#Create a ...
- 307
8
votes
2
answers
5k
views
Change a raster from longitude display (-180, 180) to (0, 360)
Using R software, I want to modify the attached raster in order to visualize it centered on the Pacific Ocean. Indeed, I need to show the entire Oceania: in my opinion I have to shift from (-180,180) ...
- 365
8
votes
3
answers
7k
views
Open JPEG2000 (Sentinel 2) in R
Is there any way I can open Sentinel 2 JPEG2000 file (.jp2) using R? Or more specifically with the {raster} package in R?
I keep getting the Error message that .jp2 is:
not recognised as a ...
- 213
8
votes
2
answers
5k
views
How to calculate distance on large raster in R?
I'm trying to do some raster algebra and one of my layers is a distance from a coastline layer. I'm using rasters with 12.5m resolution and when I use the distance function, I seem to run into memory ...
- 440
8
votes
1
answer
5k
views
R raster Package Moran's I interpretation
I am using raster package to calculate the local Moran's I . The example gives the range of Moran's I between - 1 to 2.47. On my own data I have see the value range -3.070423 - 7.228558 How can Moran'...
- 330
8
votes
1
answer
3k
views
How do I get rid of edge effects while using focal in R to smooth a raster?
I am trying to use R with the focal function from the raster package to smooth raster images.
I am working with Radar images that have already been preprocessed. As part of that, some calculations ...
- 83
8
votes
2
answers
7k
views
Filling NA gaps in raster with R?
I have soil data rasters from SoilGrids.org that have some small holes with NA cells (White spaces in the image) that I want to fill using some interpolation method to get a more spatially continuous ...
- 505
8
votes
3
answers
6k
views
R raster predict using lm() time series
I try to make a prediction in raster using linear regression based on past rasters but I can not capture the lm() model in order to feed it to predict().
#
# calculate regression in a raster stack (...
- 191
8
votes
1
answer
2k
views
How do I tile raster input to speed up display in R Shiny programs?
Disclaimer: I have very little GIS experience
I've been working on a project in R that involves displaying large raster maps in an R Shiny interface. I am using the leaflet package for display. The ...
- 183
8
votes
1
answer
1k
views
Warning message using writeRaster() - not updated for proj >= 6
Using the code below to write a raster to disk:
library('raster')
r <- raster(nrow = 5856, ncol = 9141)
r[] <- 1:ncell(r)
writeRaster(r, tempfile(fileext = ".tif"), ...
- 359
8
votes
1
answer
5k
views
Setting CRS of raster to EPSG 3035 using R
I am trying to set the CRS of a raster file with the following code:
library(raster)
r<-raster(xmn=0,xmx=10,ymn=0,ymx=10)
crs(r)<-CRS("+init=epsg:3035")
The warning message is:
...
- 283
8
votes
1
answer
4k
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 ...
- 81
8
votes
0
answers
1k
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 ...
- 99
7
votes
3
answers
1k
views
Find maximum extent out of list of shapefiles (in projected coordinate system) in R
I have a script where I crop a list of rasters by the extent of one of many shapefiles. So far all of by shapefiles have been such that I could manually select the one with the largest extent (i.e. ...
- 916
7
votes
2
answers
5k
views
Transforming geostationary satellite image to lon/lat
The ICARE Data and Services Center distributes the SEV_AERUS-AEROSOL-D3 product in HDF5 format (http://www.icare.univ-lille1.fr/archive/?dir=GEO/MSG+0000/SEV_AERUS-AEROSOL-D3.v1.03/).
The main ...
- 793
7
votes
2
answers
4k
views
Creating a raster of the residuals of a regression between two rasters
I am trying to create a raster of the residuals of a regression between two rasters. i.e. I would like to carry out a regression of one raster against another of the same extent and plot the residual ...
- 71
7
votes
1
answer
999
views
To project, or not to project? Extracting raster values with R
I have a raster from which I need to extract values at point locations using raster::extract(raster_stack, points_sf).
The raster is at 30 arc-second resolution and came from WorldClim with ...
- 1,671
7
votes
2
answers
21k
views
Save WMS layer to TIFF raster
In QGIS, I have a WMS layer. I am saving it to my hard drive by right click > "Save As...". Just like in HDunn's answer here. This is about my understanding of the topic, already this code is strange ...
- 167
7
votes
2
answers
5k
views
Generating random points inside raster boundary using R?
I have a projected raster shown in the image below (left). I want to generate random points inside the raster like the middle image. However, the result I am getting is the same as the image on the ...
- 359
7
votes
2
answers
11k
views
How to write every raster from a list of rasters?
I have created a list of rasters - "norm" and run a several loops. Now I would like to write every created raster from "norm" (containing 1 layer) into one raster, having its specific name.
# I can ...
- 3,386
7
votes
1
answer
9k
views
Adding title beside raster spplot legend
After studying for a while how to create a chart from a raster object, I got almost everything I needed except to add a title to spplot's legend.
What I tried:
To use mtext("XXX (m)", side=...
- 10.3k
7
votes
5
answers
13k
views
Reproduce raster with same extent, and same number of columns and rows?
I have two raster A and B. A and B have the same grid size but different extent.
How can I make A have the same number of columns and rows, as well as the spatial extent of B?
- 2,215
7
votes
4
answers
7k
views
R Raster package: write NetCDF with time dimension
I am writing a rasterbrick with multiple layers to a netcdf file using the raster package in R:
writeRaster(gridfile, "Data", "CDF", overwrite=TRUE,
varname="Data",varunit="mm.d-1",longname="...
- 71
7
votes
2
answers
2k
views
Calculating block statistics from land cover raster using R?
I have a raster (5 x 5 m resolution) representing land cover. Each cell contains a integer value (from 1 to 10) representing a total of ten land cover classes (e.g. 1-forest; 2-agricultural areas; 3-...
- 371
7
votes
1
answer
6k
views
Importing raster with R from File Geodatabase?
How can I import a raster file from a gdb into R?
Name of raster file: Cont_maturite
in gdb : CAROPER_04151.gdb
In wd: c:\test\caroper
- 71
7
votes
1
answer
8k
views
Using a fixed palette range to plot an NDVI raster in R
I would like to plot an NDVI raster with rasterVis packages using the normalized colors from red to green. I don't understand how fix the color scale from 0 to 1 even if my raster value are between 0....
- 729
7
votes
3
answers
3k
views
Kriging with barriers in R?
I wonder if there is a way to interpolate xyz points in a raster within certain bounds using R? In ArcGIS this is called interpolation with barriers. I wonder if there is something similar in R? I ...
- 71
7
votes
1
answer
740
views
Getting a raster into GRASS and back out again: `rgrass7` readRAST not preserving dimensions
I am trying to get a raster into GRASS from R and back out again using the rgrass7 package. Getting the raster in seems to be no problem. However, when I try to get it out with the readRAST function ...
- 1,370