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Questions tagged [r]

Statistical computing language and software environment.

0
votes
1answer
24 views

Order features in a spatialpolygonsdataframe in ggplot2

I have a spatialpolygonsdataframe with many overlapping features. I want to create a map in which the smaller features are displayed on top of the larger ones so that the small ones aren't fully ...
0
votes
2answers
150 views

Land Cover Change Classification in R

I have two Land Cover (LC) classification raster over the same area and the same cell size. One from the year 2018 and the other from the year 2014. Both raster are classified with the values 1 - 6, ...
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 ...
0
votes
0answers
25 views

Overwrite my shapefile in a temporary file

I would like to save my shapefile in a temporary file (named after the name of the shapefile). I would like this one to be saved after the transformation of the coordinate system. For the moment, my ...
3
votes
2answers
323 views

random sample of raster cells based on multiple classes in R

I have a raster dataset that is classified into vegetation classes. I would like to randomly sample from the dataset based on the vegetation classes, but not sure how to do it. Here is some example ...
1
vote
1answer
27 views

Batch reading features from many Geodatabases in R

I would like to learn to batch import from many geodatabases at once and merge the files together into a new unified shapefile. All of the GDBs and Features have a similar name and file structure. For ...
60
votes
6answers
139k views

Opening shapefile in R? [closed]

I need to open a shapefile from ArcMap in R to use it for further geostatistical analysis. I've converted it into ASCII text file, but in R it is recognized as data.frame. Coordinates function doesn't ...
0
votes
1answer
575 views

spTransform error (unable to find inherited method for function spTransform)

I am trying to reproject a shapefile. For example, the land shapefile from Natural Earth. library(sf) shape <- read_sf(".../ne_10m_land.shp") shape_proj<-spTransform(shape, CRS("+proj=gnom +...
0
votes
1answer
105 views

How to extract raster attributes by lat/long location?

How can you extract an attribute value from a raster from a point (lat/long)? Example data: Raster with attribute table - value of interest is temperature I have a list of points with lat/long ...
0
votes
1answer
10 views

Plot GeoTIFF using tm_rgb from R tmap package

I've exported a raster object from QGIS into GeoTIFF format and imported it into R as a raster brick using the brick() function from the raster package. The file is too large to share but it imports ...
2
votes
5answers
1k 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 ...
1
vote
1answer
20 views

How to build polygons from buffered points and merge overlapping ones using R?

I have a sample of 3 groups of points which are similarly spread within their groups. > pts x y [1,] 453067.5 364073.5 [2,] 453066.5 364072.5 [3,] 453068.5 364072.5 [4,] ...
1
vote
0answers
23 views

Automatic zoom when uploading shapefile R

I would like to set a zoom on the shapefile's canvas when it is uploaded. is there a function for that? Here is my script that allows adding the shapefile after reading with OGR : observeEvent(input$...
1
vote
0answers
17 views

How to convert from Large RasterLayer to Formal RasterLayer class in R?

I'm a bit confused about types here. While I'm loading a image: tif = raster(paste0(path)) I get some "Formal Class RasterLayer" object. But while I change it's matrix of values, for example: idx &...
-1
votes
1answer
39 views

Converting Kelvin to Fahrenheit in raster stack using R?

I have a raster stack with 372 layers with Kelvin temperature. I want to convert Kelvin to Fahrenheit. I know the function, but do not know how to adjust the code so it can be applied to all layer in ...
3
votes
1answer
47 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 ...
6
votes
4answers
6k views

Dissolving ploygons in QGIS or Grass to new polygons of defined population sizes?

I have a shapefile with 3800 polygons representing the smallest administrative areas in Ireland. Many of these, in rural areas, have tiny populations, under 100 people. In urban areas, all would have ...
0
votes
1answer
65 views

Performing trend analysis with R?

I have data of monthly temperature for 60 years. I want to analyze the trend for the monthly temperature in R. How do I construct R Code which would analyze monthly trend over the time series to ...
0
votes
0answers
14 views

How to bind points with polygons extracted from raster using R [on hold]

I have big tiff and load it using raster: tif = raster(paste0(path)) Next, I can extract all the polygons from the file (using some value P of interesting layer value): rtp = rasterToPolygons(tif, ...
0
votes
0answers
26 views

How to calculate mean for each raster layer in a stack? [on hold]

I have a data of monthly temperature (with several values in each layer (i.e temperature values for a month)for 31 years (372 layers). Now have to calculate mean for each month for 1980-2010 and save ...
1
vote
0answers
19 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 ...
-3
votes
0answers
21 views

Creating 3D image from HGT DEM file? [duplicate]

I tried Displaying 3D raster/vector in GRASS from command line?: Error there is no nviz in my GRASS 7.6.x Already tried this too: Error m.nviz.image bad server connection Already see this and the ...
1
vote
1answer
35 views

Save a shapefile in a temporary file

I would like to add a line after the transformation of my shapefile in order to save it in a temporary file. uploadShpfile <- reactive({ if (!is.null(input$shp)) { inFile <- input$...
0
votes
0answers
22 views

Simple “Clip” geopackage with all attributes using R/ArcGIS/QGIS [closed]

I have recently discovered geopackages and SQLite. I have a geopackage containing a shape (main.stand) and multiple tables (main.assortment, main.treestand,...) of individual forest stands. Some of ...
1
vote
1answer
91 views

R levelplot: How to shade some pixels out to show statistical significance

I am posting this also on stackoverflow because the topic is in the middle between GIS and R programming. I need to include statistical significance in a map in R using rasteVis, which is based on ...
0
votes
0answers
20 views

Extract time series from NetCDF stars proxy object

I'm trying to extract a time series from a netCDF file opened as a stars_proxy object in R. Looking at the raster to stars mapping table, I should use the aggregate function. But I'm getting a CRS ...
2
votes
1answer
39 views

Configuring lidR catalog to overwrite raster output (with different extension)?

I have a small issue with configuring the lidR package for parametrizing the extracted raster files with grid_metrics() function. My question is how to set in the catalog options that: be able to ...
4
votes
1answer
23 views

Using lidR to count number of pulse returns at different intervals?

I am trying to get the number of pulse at different height interval. I have used the lidR package to do this before with the code below but it seems that recent update in the package breaks my code. ...
0
votes
1answer
48 views

Setting origin raster to resample using R?

I need to resample a raster from nrow= 467, ncol=805, res=0.0416667 degree to nrow=2335, ncol=4025, res=0.00833333 degree. Basically make the pixel size smaller, because I have too many small polygons ...
1
vote
1answer
22 views

R: rasterize SpatialPolygonsDataFrame and keep factor field

I want to rasterize a SpatialPolygonsDataFrame and keep the values of a factor column. Consider the following code (from Processing vector to raster faster with R): library('raster') library('rgdal'...
1
vote
3answers
38 views

Error in Converting XY Coordinates to Lat-Long Using r proj4 Library

I am trying to write a script that will allow my colleagues to easily convert XY coordinates into lat and long. The idea here is to take a spreadsheet with only X and Y available and create a new ...
1
vote
0answers
34 views

Raster projected in Google Earth Engine showing weird values within R

I classified a raster in GEE and I am trying to work with the same within R. I have 7 land cover classes and when I view the output in R, I get something that does not make sense. Please see the ...
2
votes
3answers
138 views

R - Create multiple linestrings from multiple coordinates

I have a dataframe with two sets of coordinates X,Y and prevXal,prevYval and I would like to make linestrings column wise, and create an sf object of the same number of linestrings as rows in the ...
3
votes
0answers
43 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 ...
1
vote
1answer
16 views

Using Formal Class RasterLayer as RSAGA input and otput

Is there a way to use the data from the R global environment object as input for an rsaga.geoprocessor alghoritm? And if yes, can be the output also saved as a same object? I am writing chain ...
-1
votes
0answers
22 views

Zipped shapefile upload, R Shiny [closed]

I've created a feature to import a shapefile (via .dbf .prj .shp .shx) but I would prefer to import only a zipped shapefile. How will I be able to transform this function? Here's my code : server.R ...
-1
votes
1answer
33 views

Calculating new raster metrics without polygonizing in R?

I have an enormous number of large rasters representing tree canopies. Every individual canopy has a unique number that is assigned to each pixel that is part of the tree. I am working with R and the ...
2
votes
1answer
93 views

Building footprint polygon from LoD1 CityGML 2.0 using R and sf?

I have LoD1 building data from a federal agency in Germany in the CityGML format. I would like to import and strip the data into R to get only the footprint of the buildings and an attribut about the ...
0
votes
0answers
33 views

Converting non-conformable multi-layer rasters to a big data frame

I want to create a big data frame from all rasters which are from all folders. All rasters share the same properties such as rain etc. and same x&y in the same folder, but they don't share the ...
1
vote
1answer
40 views

After calling projectRaster in R, missing right edge of world map when plotting with ggplot

I'm using projectRaster and rasterToPoints in R to get a dataframe with lat/lon coordinates for plotting in ggplot but I seem to be losing the right edge of the map (New Zealand). I'm not sure if this ...
1
vote
1answer
32 views

Using tmap for points in R?

I'm having a problem using tmaps to map out points in R. The data is taken from the Chicago data portal, and I was able to turn it into a sf object using the code below. However, when I try to use ...
2
votes
1answer
64 views

Why a laz file warns: 'return number' greater than 'number of returns' in R?

Reading a laz file with the lidR package in R I have the following warning. What does it means? las = readLAS("chmp15.laz", filter = "-drop_z_below 0") #> Warning message: #> Invalid data: 8895 ...
5
votes
1answer
119 views

How to assign (or project) CRS to LiDAR file in lidR?

Can someone enlighten me if there is a difference between initializing a CRS object using the EPSG code versus just the +proj string read from a shapefile? Consider the following objects: A ...
0
votes
2answers
459 views

Creating loop for Lines data (spatial data)?

I am trying to build a lines shapefile with the contour lines from the 20 meters isobath from along the East African coast. This contour line of 20 meters has different segments and I have this ...
0
votes
0answers
24 views

Using R for analysing relations between administrative borders (neighborhood of polygons) and voting results (or void votes)

What would be the relatively simple way to verify if there is a relationship between administrative borders (polygons) and voting results (like: void votes). This would be used to verify if voting ...
2
votes
1answer
125 views

Dividing a large raster into blocks for iteration in R

I have very big rasters for processing (#pixels >1,5*10^10) for this project I am working on. Simple functions such as finding the area of a pixels with a particular value, across the entire raster 1) ...
0
votes
0answers
36 views

Getting census tract centroids in R [closed]

I am trying to get the lat, long for census tract centroids using gCentroid. This is giving me very strange results, with multiple centroids per census tract. ctract <- st_read("tl_2016_06_tract....
0
votes
1answer
25 views

How to get WMTS tile coordinates?

What can I do with the given information: I don't know where I am in the World having some particular tile. It's only an ocean (or sea). "https://services.arcgisonline.com/ArcGIS/rest/services/...
0
votes
1answer
31 views

Using st_read to create an owin in R

I have updated a program because readShapePoly has been replaced by st_read. Changing from: unzip(paste(mdir, "AU_Vic_POA_2011.zip", sep = "")) boundary.shp <- readShapePoly("...
1
vote
1answer
36 views

sp::over vs sf::st_intersection in r

I was wondering why sf::st_intersection() takes too much time, in comparison with sp::over(); I use sf for pretty much all of my geospatial workflows (I was used to sp as well), and more and more ...