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59 views

Using R to combine long/lat data into UK region polygons

I've a CSV file with geoinfo: JobSeekerId LocationId UpdatedDt EndDt Latitude Longitude Country Name JobTitle CompanyName ...
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35 views

Transforming GIS based XY data (polygons) so that they overlap in R

So I'm attempting to come up with the average shape of these polygon features as a part of my masters research. To do this, I want to run a shape analysis of GIS-based X-Y data using the shapes ...
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3answers
190 views

R: How to get latitudes and longitudes from a RasterLayer?

I am an absolute beginner of geographic data, so please, forgive me if the question is not appropriate. I downloaded data from NCDC NARR and managed to load into R using the raster package. I would ...
2
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1answer
58 views

How to extract values based on names of rasters?

I have a raster r that contains values for each grid cell (which vary from one cell to another). I have other 24 rasters where the names of the rasters are: the name of r1 is data-00.img, the name ...
2
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1answer
40 views

Georeferencing in R Based on the Four Corners

I have a raster image (photograph) that was taken from a helicopter. Along with that raster image, the system also tells me the positions of the four corners of the image in a different file. I have ...
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43 views

Count objects in polygons

I have a .txt file containing the coordinate of the two polygons in the picture below as well as coordinates for each of the lines inside the polygons. Could anyone help to count each line inside ...
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13 views

DEM and r2stl() distorted models?

If I import a dem file into R and then call as.matrix() on it, I can access z values. I want to create a 3D model, but I'm getting strange results. Most of my dems are spiky and if they are smooth I ...
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2answers
41 views

How to read ArcGIS files in R?

I am new to using spatial data in R. So far the tutorials I have seen consist of using maptools, map, ggplot2 and rgdal to open ".shp" files along with ".csv" files to plot the polygons/ points using ...
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98 views

How to turn shapefiles into raster and aggregate them into one raster

For example i tried this but it doesn't work rast_a<-raster(extent(shp_1)) res(rast_a)=100 rsh<-rasterize(shp_1,rast_a) rast_b<-raster(extent(shp_2)) res(rast_b)=100 ...
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54 views

Re-sample raster to acre grid using ArcGIS Desktop or R?

I have a 1m classified landcover raster layer that consists of values 1-4 representing various land covers. I need to resample this layer to an acre grid. Each acre in the resultant grid should ...
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1answer
52 views

plot 3D graph based on raster pixel values

I am new to raster data. I have a raster tif file with population density value in each grid cell. I am interested in plotting a 3D graph based on raster values in ArcGIS or R. The similar graph is ...
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77 views

How to convert a spatialpolygon to a SaptialPolygonsDataFrame and add a column to the atrribute table

coast<-readShapeSpatial("coastline.shp") landc<-readShapeSpatial("landcover.shp) ro<-readShapeSpatial("roads.shp") bc<-gBuffer(ro,width=100) landc$ratings=1 ...
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1answer
87 views

Monthly weather averages using NCEP/NCAR Reanalysis data

I'm a political science grad student and I've recently (and probably foolishly) committed to dipping my feet into GIS. Right now I need to build a table that has monthly precipitation and temperature ...
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2answers
72 views

A raster map without a legend?

I simply download a map from here http://neo.sci.gsfc.nasa.gov/view.php?datasetId=MCD12C1_T1. this map is a tiff file. mapd <- raster("C:\\MCD12C1_T1_2011-01-01_rgb_1440x720.TIFF") plot(mapd) ...
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38 views

DEM files and r2stl()

In R The Volcano dataset has elevation values, but is not a DEM file. How can I convert my DEM files (from earthexplorer.usgs.gov) so that the I can access all the elevation values in a matrix (what ...
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1answer
60 views

How to create a US map in R with separation between states and clear labels?

I was trying to figure out how to create a map like down below in R on the Stack Exchange but maybe that's the wrong community and the GIS side is a better spot. Currently, I'm able to add the ...
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1answer
23 views

Iterative Mean of Means Infinite Loop for calculating H-t Index

I'm trying to create a function that will calculate an Ht-Index for Quantifying the Fractal or Scaling Structure of Geographic Features (but am new to R) which basically just finds nested means of ...
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85 views

Performing Maximum Likelihood Classification in R

I'm trying to perform maximum likelihood classification of landsat imagery using R, I have been searching for a package that implements it but so far I haven't found it. What is the easiest way to ...
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1answer
37 views

Choosing R package for discrete choice model?

I am at a loss as to which R package and approach to use for my modeling. The background is: I have a transportation survey dataset combined with many other GIS datasets. I am attempting to ...
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1answer
37 views

Mapping Disease Incidence in the Northeast in R

I am trying to map disease incidence by county in states in northeastern states in the US. I have the shapefiles for the entire US but I am having a difficult time deleting the states that I do not ...
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49 views

Error of memory for vector allocation while kriging [duplicate]

When I run the krige.conv function from the geoR package in R: kc <- krige.conv(as.geo,loc=prd.loc,krige=krige.control(cov.pars=c(0.29,0.79))) it throws me the following error: Error: cannot ...
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1answer
41 views

legend colour with specific value

i have model plotted in R base<- raster("example.tif") plot(base) image i'd like to change value (0,5,10,15,20,25) breakpoints<-c("0,5,10,15,20,25") plot(base,break=breakpoints) Error in ...
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31 views

ArcGIS implementation of an R-script for estimating spatial autocorrelation

How do I implement the following in ArcGIS? rho.from.data <- function(ras){ require(spdep) require(maptools) #-- Generate Spatial Pixels data frame from raster file --# r2r <- as(ras, ...
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3answers
114 views

Plotting Netcdf data. How to get right projection?

Maybe it's very easy for someone to fix, but I'a a new one in R, so I really need help. I/m trying to plot data containing lat, lon and variable (nmf2). The grid isn't a regular one, so there are some ...
2
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1answer
44 views

Extracting intersection areas in R

I have two polygons. One contains fields(X,Y,Z) and the other contains soil types (A,B,C,D). I want to know what area of every field contains which type of soil. I tried the following: ...
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157 views

Calculate distance between a set of points: lat and long in QGIS or R

I have shapefiles containing the location of several individuals along several months. Positions were documented with a 30 minutes interval. Tables contain the following data fields: collar (ID), ...
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1answer
39 views

Sampling one shapefile with polygons of another using R?

I have two shapefiles that partially overlap. One (the bigger one) consists of several polygons which represent fields I am interested in. The second, is a rectangular shape that overlaps about 30% of ...
0
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1answer
45 views

chi-squared for two rasters in R

I am kind of new with statistics. I have two raster with categorical values and I want to get chi-square. How can I do this using R? Rasters have the same region and same resolution. Is chi-square ...
3
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1answer
49 views

CRS not embedded by maptools in R

I'm using the maptools package in R to merge some data to a shapefile. When I open the original input shapefile in QGIS, QGIS automatically picks up on the CRS. When I open the output shapefile from ...
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1answer
31 views

ggplot2 plots polygons with wrong topologies

I'm trying to plot polygons in R using ggplot2. In GRASS, QGIS and normal R the map renders fine, but ggplot2 seems to have some kind of topological difficultes I can't explain. With normal R it looks ...
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2answers
100 views

What is the “best” way to automate the GIS slope and aspect algorithm?

I am currently obtaining slope and aspect of roofs using ArcGIS as follows: Mosaic several Lidar .asc files to new raster Extract by mask using Mastermap building outlines to get hold of just the ...
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1answer
120 views

Overlaying lines and aggregating their values for overlapping segments

I have a number of routes (5 in this example data) stored in a SpatialLinesDataFrame called r. These have different origins but all converge on the same destination (Manchester Airport): Each ...
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1answer
53 views

Conditional statement, apply different equation based on raster value R

I am trying to find the best way to apply a set of equations to a raster conditional on values in a separate raster. For example, suppose r1 has the values of interest and raster 2 (r2) is a raster ...
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2answers
31 views

How to compute climatology of 3 days moving averages for rasters pixel by pixel?

I have one year of datasets that I want to compute the climatology of 3-day moving averages and then I subtract this climatology from the original values for each pixel. example: # Set up the ...
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60 views

polygon shapefile R extract issues

I'm trying to do simple RF classification in R based on https://gis.stackexchange.com/a/39103/48810. The code I am using is as follows: require(sp) require(rgdal) require(raster) ...
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48 views

Optimal distance and power exponent in IDW

I want to apply IDW interpolation for my region of interest, and through leave-one-out cross validation I want to find the optimal values for the distance parameter and the power exponent. I know that ...
5
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1answer
148 views

Calculating road density in R using kernel density

I have a large (~70MB) shapefile of roads and want to convert this to a raster with road density in each cell. Ideally I'd like to do this in R along with GDAL command line tools if necessary. My ...
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27 views

How to export multiple class training data from ArcGis into R?

I want to perform some machine learning classification of images using R. I'm having issues finding out how to export my training data from ArcGis into R and I'm looking for some help. Currently I do ...
2
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2answers
124 views

How calculate pixel by pixel the mode (statistic) of multiple rasters (geotiff)?

I have 12 land cover maps, and I would like to calculate the mode to each pixel of the 12 maps (they have the same resolution and dimension). I mean, the final map would be the mode for each pixel of ...
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26 views

How to avoid a problem of one pixel when doing non-linear regression?

I am ruining a non-linear regression using nlsLM from package:minpack.lm for multiple rasters (pixel by pixel). My initial values may be appropriate for some pixels but not for others.When I run the ...
3
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3answers
193 views

Assigning RGB values from Geotiff image to LiDAR data, using R

I have given a Geotiff image and its corresponding Lidar data (x,y,z) in UTM coordinates. I need to merge the Lidar data with the RGB values from the image. That means, at the end, I need to plot ...
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1answer
66 views

Can't import libraries to rsaga

I get this error when I'm trying to import a raster to RSAGA: > rsaga.import.gdal(paste(rast_name, ".tif", sep=""),"RASTER", env= my_env) Module 'GDAL: Import Raster' not found in SAGA library ...
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1answer
58 views

Extract area of polygons inside larger polygon and sum their values to a new column

I have two landcover classifications (as shapefiles) created using eCognition. "Level0 (FID)" consist of larger polygons and "Level1 (FID, ClassName, Area_Pxl)" of smaller polygons within these. I ...
6
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1answer
116 views

How to perform a non-linear regression pixel by pixel?

Using nlsLM from Package ‘minpack.lm’ is straightforward for a simple example like this: MODEL:y=(exp(a*x+b*z+c)+d)^f x=c(0.5,0.3,0.2,0.4) z=c(0.1,0.6,1,0.9) y=c(0.2,0.3,0.9,0.9) ...
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2answers
128 views

How to load projection along with raster in R?

Why the operation myraster = raster("test.asc") does not load the associated projection file test.prj located in the same directory as test.asc? Does raster() need a specific argument? It seems ...
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34 views

crop shp file leads to different results for same extent

I cropped a shapefile to a smaller extent (my AOI - area of interest) - to work with a reduced working directory. During my workflow I rasterize the shapefile. Here is my problem: I saved both of my ...
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1answer
59 views

Single point in R

My question might be very simple. I want to create a single point (with xy coordinates) in a specific region, in a specific position. I don't want to do that with qgis I want to do that in R. Is there ...
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2answers
140 views

Join spatial point data to polygons in R

I am trying to perform a spatial join between point data and polygon data. I have data that indicate the spatial coordinates of an event in my csv file A and have another file, shapefile B, that ...
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1answer
36 views

Add information from polygon to raster in R

I would like to add information from a spatial polygon to a new raster. r <- raster(nrow=10, ncol=10) r[] <- runif(ncell(r)) * 10 xym = matrix(c(0,0,0,45,45,45,45,0),4,2,byrow=T) ## create ...
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1answer
79 views

unsupervised random forest classification in R

I want to compute an unsupervised random forest classification out of a raster stack in R. The raster stack represents the same extent in different spectral bands and as a result I want to obtain an ...