All Questions
1,780 questions
0
votes
1
answer
24
views
Date in CRU data is starting from 380 instead of 1, since unit is days since 1900-1-1
I ran the following line of command. Below result show that:
" time Size:1380 *** is unlimited ***
long_name: time
units: days since 1900-1-1
calendar: gregorian
daily_rain <- "...
0
votes
0
answers
36
views
Date is missing in CRU data
I used the following code to extract "Climate research Unit" climate data. However extracted data showing "Date : NaN, NaN (min, max)".
pre <- brick("cru_ts4.06.1901....
2
votes
2
answers
1k
views
How to remove NA value of legend when using R tidyterra?
I downloaded the MCD12Q1 data (land cover and category type data) by MODIStsp package, and I want to plot it using tidyterra package.
For example,
library(terra)
library(tidyterra)
library(tidyverse)
...
- 329
0
votes
1
answer
162
views
Calculate argmax and second argmax of a RasterStack in R
I need to calculate the argmax (index of the maximum) and index of the second maximum of a RasterStack in R. That is, for each pixel of the image, I need to evaluate in which index (layer) is the ...
- 1,044
1
vote
0
answers
456
views
Making map with marginal graphics like rasterVis::levelplot(margin=T)
I love rasterVis::levelplot(margin=T) because its marginal graphics show the column (x)
and row (y) summaries of the Raster object. I think it is very helpful to visualize the raster.
Package ...
- 329
1
vote
1
answer
74
views
Assigns geographical locations to the pixels in isolate drone image in R
In my example, I have a single dji image in *JPG:
library(terra)
single.image <-stack("https://github.com/Leprechault/trash/raw/main/DJI_0274.JPG")
plotRGB(single.image, r = 3, g = 2, b =...
- 175
0
votes
1
answer
2k
views
Errors reassigning CRS of SpatRaster using terra::projectRaster and raster::project
I have the following SpatRaster object called pred_th:
dimensions : 162, 87, 1 (nrow, ncol, nlyr)
resolution : 0.08333333, 0.08333333 (x, y)
extent : 43.25, 50.5, -25.58333, -12.08333 (xmin, ...
1
vote
1
answer
498
views
Create several raster layers based on one layer
The terra::app() function accepts one or more layers and a function, and usually (?) returns just a layer with results. However, how to apply a function to one layer that returns more than one layer?
...
- 992
2
votes
1
answer
147
views
Raster R package, points outside the grid
I am posting my issue in this community as I did not get satisfying answers in stackoverflow, hoping to get a solution here.
I am working on a spatial simulation and I created spatial points, but when ...
- 23
0
votes
1
answer
234
views
Process WCS data from EMODnet using R
edit: setting mode = "wb" to download the file is crucial for correct reading using solution by Spacedman
I'm trying to get raster data on depth from EMODnet into R to analyse, using the WCS ...
- 103
0
votes
0
answers
96
views
Reproject netcdf4 raster works for one dataset but not the other in R
I wrote code to reproject the OISST NetCDF to my desired projection, and it works correctly. However, when I run the same code on the NCEP NCAR Reanalysis data, I get something wrong. Not sure why ...
- 1
1
vote
1
answer
387
views
Converting large number of NetCDFs to single raster using R
There are ~87,500 NetCDF files of a global dataset that must be stacked and the values averaged to create 1 raster. My machine does not like this... I've written nested for loops that, despite ...
- 77
0
votes
1
answer
353
views
Rolling (moving) window linear regression - extract residuals
I want to perform linear regression with a rolling (moving) window with size 5 using raster data.
I tried a code using the raster package and the function localFun, and when I am trying to export the ...
- 1,167
1
vote
0
answers
87
views
Calculate by cell statistics of Image Collection in (R) Google Earth Engine?
I am using Google Earth Engine in R via the rgee package. My goal is to calculate median NDVI for each cell in an image collection. I have an image collection gathered via:
#This is not a reprex
...
- 452
1
vote
1
answer
880
views
Aggregate raster in R and get count of contributing pixels
I have a raster with some NULL values. I need to aggregate the raster to a coarser one, and get a count of the pixels that are being aggregated (for every output pixel), excluding the NULLs. I'm ...
- 31
0
votes
1
answer
454
views
Raster file with all Bing Maps quadkeys
I'm looking for a raster file that has all quadkeys of Bing Maps for a given zoom level. Does that exist? If not, how could I create it myself in R?
I have spatial data as a set of shapefiles (none of ...
- 1
0
votes
0
answers
1k
views
Why is coord_sf needed to plot a geom_raster with ggplot2?
Why is coord_sf() needed to plot a geom_raster in ggplot2 and what exactly does coord_sf() do?
According to ggplot2's Map project's documentation: coord_map projects a portion of spherical earth onto ...
- 916
0
votes
2
answers
337
views
Double indexing and looping over raster lists in R
I have a list of 63 rasters. They are the same extent, resolution, projection, etc. Because I extended 62 rasters to the maximum extent of the 63rd, I introduced NA values. However, these are relative ...
- 51
1
vote
0
answers
45
views
Getting equal number of cells within rasterstack using R
I have a raster_stack with 3 rasters. I made them the same resolution, extent, projection so that I could combine them into the stack. So, I expected each raster to have the same number of pixels. The ...
- 51
0
votes
1
answer
260
views
Draw a polygon over PNG image R
I have a PNG image wich I have opened in R and in order to give coordinations converted into a SpatRast object with the following code:
library(terra)
r <- rast("yanomamis.png")
#Warning: ...
- 15
0
votes
1
answer
464
views
Comparing smoothing algorithms in R
I am comparing smoothing algorithms in R. More specifically, the raster.gaussian.smooth from the spatialEco package and the focal from the terra package. Visually, the results look similar but the ...
- 1,167
0
votes
1
answer
653
views
Aggregate raster using gaussian smoothing as a custom function/Units of the sigma
I am trying to aggregate a raster using a custom function and the terra package. For the custom function I am using a Gaussian smoothing. When I try to run the aggregate function I am getting this ...
- 1,167
0
votes
1
answer
536
views
Problems extracting ERA5 data with exact_extract in R
I used polygon to extract the nc file, which is the temperature data of ERA5, but when using stack and using the exact_extract function, there were warnings and errors.
> rasdata <- stack("....
- 1
3
votes
3
answers
4k
views
Create empty raster with dimensions, pixels size and CRS of another raster in R
I am trying to create an empty raster layer and I want this empty raster to have the same dimensions, pixel size and CRS based on another raster, but no pixel values.
I am getting errors when I try to ...
- 1,167
5
votes
2
answers
1k
views
Calculate raster cell area as function of latitude?
Raster used available here: https://www.dropbox.com/s/xn7hdll2op5zcc9/MAP_global.tif?dl=0.
INTRODUCTION:
The resolution of a raster is commonly related in degrees, e.g.:
library(raster)
r <- ...
- 77
0
votes
1
answer
1k
views
Unusually formated NetCDF to raster in R
Having issues relating information stored in an NetCDF in a way I haven't seen before.
nc file located here:
https://www.dropbox.com/s/x1eexenioclwe0l/ISCCP_HXG_total_PAR_1984_01_01_03.nc?dl=0
Can ...
- 77
1
vote
1
answer
359
views
Modify raster coordinates (wrong projection) using stars or terra
I downloaded a raster image from the following address, which corresponds to rivers and streams in the Barcelona area.
https://geoserveis.icgc.cat/icgc_geotecnicbcn25m/wms/service?REQUEST=GetMap&...
- 157
0
votes
0
answers
58
views
Reproject altitude data to make it coincide with SpatialPolygonsDataFrame
I am trying to get an altitude raster to coincide with a working spatial polygon dataframe that shapes the region with data from an .nc file. The .nc file, and thus the derived spatial polygon ...
- 129
1
vote
3
answers
159
views
Forest patch centroids are not located in patches using landscapemetrics in R
I am using the R package landscapemetrics to find forest patch centroids in a landscape. The given function to find patch centroids is get_centroids(). The centroids returned from get_centroids() are ...
- 452
4
votes
1
answer
1k
views
R Focal Function - Terra vs Raster
I'm not sure why the focal function I've been using in Raster does not work with Terra. This simplified example uses a custom function to apply the focal filter only to pixels with a value of 0 and ...
0
votes
2
answers
1k
views
How to read and write raster matrix data with R (raster package and image processing)?
I'm using R for morphological operations on geo-rasters.
The packages mmnand and EBImage offer morphological operations. However they can't work with georeferenced rasters, but operate on a matrix (or ...
- 2,554
0
votes
1
answer
267
views
I am using BFAST to do a time series analysis of LST and I am getting NaN errors
This is the blog post I refer to, https://philippgaertner.github.io/2018/04/bfast-preparation/, and the author's code is as follows:
# NDVI data
data(tura)
selected_pixel <- 90 represents a ...
- 1
3
votes
2
answers
408
views
Overlay raster (h5 files) with shape files to get night light data in R
I am trying to combine ".h5" nightlight data files of Hawaii with zipcode-shapefile from Hawaii, but I am getting the following error:
#Error: [crop] extents do not overlap
The R codes are ...
- 33
2
votes
0
answers
169
views
How to address NA in pixel regression (local computation) with R terra package
For example, I have five NDVI TIFFs and five precipitation TIFFs. I used the code provided by Robert (https://stackoverflow.com/questions/63831287/extracting-p-values-from-lineair-regression-on-raster-...
- 329
1
vote
1
answer
4k
views
How to produce a gridded map in R where each grid cell represents the sum of points occurring in the grid?
I want to produce a gridded map where each grid cell represents the sum of points falling within the grid using R. I have seen similar questions for R here, here, and here for Phyton. But could not ...
- 11
1
vote
1
answer
255
views
Dimensions and extent changed after rast from 'xyz' data.frame
s #oringinal raster
s #check dimensions and extent
df <- s %>% as.data.frame(xy=T) #convert to df
t <- rast(df,type='xyz')...
- 329
0
votes
1
answer
473
views
How can I update a large raster with new values in R with speed?
I have a raster with 2332800 cells. Half of these cells are probably oceans and unneeded. I need to update these cells with new values. Right now I'm using a for loop and it takes a very long time:
...
- 193
0
votes
1
answer
222
views
Raster to SpatialPolygonsDataframe: close/crop polygons at the raster boundary, in R
library(raster)
# read in bathymetery raster
[https://drive.google.com/file/d/15kAcfQBJh_JiYgH-YrZZTJeeWOPd0Ysh/view?usp=sharing][1]
r = raster('./ibcso.tif')
plot(r)
# set cells above sea level to ...
- 25
0
votes
1
answer
172
views
What are the xmin, xmax, ymin, ymax values for Australia?
I am trying to crop the bioclimatic data from WorldClim.org to get environmental features only for the Australian habitat using the extent() method. Finally, I plan to combine the bioclimatic data ...
- 13
0
votes
1
answer
146
views
R Reprojecting global forest change rasters
I have been trying to calculate forest cover and forest loss in West Kalimantan Province, Indonesia, during 2000-2020. I use the gfcanalysis package in R for this purpose. Unfortunately, the minimum ...
- 1
0
votes
1
answer
463
views
Merging/mosaic raster list or raster stack
I am trying to figure out proper solution to combine >100 raster images. These raster images are individual animal utilization distributions (values 0-1) that are modeled using dynamic brownian ...
- 51
0
votes
1
answer
225
views
Monte Carlo simulation
I have an equation to calculate z from multiplying several rasters and numbers as seen below:
z <- a*b*c*d*e
The raster layers and values are as below:
library(terra)
set.seed(234)
r <- rast(...
- 373
3
votes
1
answer
4k
views
R terra::mask report error ‘Error: [mask] extents do not match’
I have a temperature tif, and I want to extract my study area.But it reports that extents do not match. I want to know how to fix it and why the extents do not match?
I think to_be_masked raster's ...
- 329
1
vote
1
answer
322
views
Use non-linear regression output to predict values across raster including categorical attributes
We are aiming to correct general snow depth values from publicly available layers at a coarse resolution (~1km) using our vegetation and other parameters collected in the field at point locations ...
- 2,027
1
vote
0
answers
52
views
Proportional allocation method for translating vector to raster format in R [closed]
My data consists of a shapefile of polygons representing municipalities in a given country. Each polygon has a population value in the shapefile's attribute table. I would like to disaggregate these ...
- 11
0
votes
2
answers
1k
views
How to extract point data (latitude, longitude) of different soil variables from SoilGrids without actually downloading the TIFF files
Objective
I have a dataset of ~200 observations, from scientific papers describing agroforestry, with associated coordinates (lat., lon.) dispersed all over the temperate world (US, Europe, China, etc....
1
vote
1
answer
722
views
Extracting variables from grid cells using R
I am trying to extract bioclimatic variables from individual grid cells. So i started loading my shapefile:
# I used the Admin 0 - Countries (1:10) dataset from Natural Earth
shp <- sf::st_read(&...
0
votes
1
answer
1k
views
How to export(writeRaster) single raster from multi-band stack/brick/spatraster one by one using R?
library(terra)
a=rast(nrows=10,ncols=10,vals=1:100)
b=rast(nrows=10,ncols=10,vals=1:100)
c=rast(nrows=10,ncols=10,vals=1:100)
test <- c(a,b,c)
for (i in 1:3)
{
r=test[[i]]
writeRaster(r,...
- 329
0
votes
1
answer
3k
views
R terra: [crop] SpatRaster has no values
I am attempting to use terra::crop() to crop 30 meter NLCD raster data to a bounding box. The final error that R returns is:
Error: [crop] SpatRaster has no values
despite the raster data containing ...
- 452
0
votes
1
answer
59
views
Trouble overlaying plots in R
I've produced a raster using IDW to make predictions across California, and now I'm trying to overlay the raster image with the border/shapefile of California.
I've ensured the CRS projections are the ...
- 1