Statistical computing language and software environment.

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272 views

Error in downloading MODIS image using R script

I am trying to download "MOD13A3" MODIS image using R script (http://r-gis.net/?q=ModisDownload) but each time it's ending in error. How to make it work ? =============================================...
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1answer
398 views

Plotting data without geographical coordinates besides the main map in ggplot2

I am trying to plot some data as a bubble chart on the world map using ggplot2 package in R. I am able to proceed as follows. # Load necessay packages library(ggplot2) library(rworldmap) library(...
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169 views

Location allocation optimization using R?

I need to allocated zip codes to offices. Each zip code has certain demand from 0 to 120 clients and each office has certain capacity from 500 to 2500. How do I do this so that: All the zip codes ...
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1answer
464 views

Difference between raster() and readGDAL()?

I am new in working with rasters and after having trouble working with them i'd like to know the difference between those two import functions. for example i did this library(raster) s<-...
3
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1answer
361 views

Reading and plotting shapefiles with a custom function in R?

I have this piece of code that want to turn into a function r <- readShapeSpatial("roads") b <- readShapeSpatial("buildings") lc <- readShapeSpatial("landcover.shp") here is the ...
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156 views

error of randomforest classification with Landsat data

I want perform randomforest classification on Landsat data. Here is some code I found from a paper. But when I run into the "classification" part, there is an error said "Error in eval(expr, envir,...
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63 views

Matching (joining) two slightly incompatible polygon shapefiles

I have two shapefiles that represent two slightly different zonings of the same area (municipality zoning and transport zones), about 3000 polygons each. Several smaller municipalities may form a ...
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2answers
44 views

Include non-raster object in overlay function in R

I have two raster objects and I would like to calculate values of the first conditional on values in the second. I am currently using the overlay function, but unfortunately I can't seem to pass non ...
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1answer
241 views

Defining projection using readOGR if the shapefile doesn't have it?

I think that by using readOGR to import a shapefile renders worthless to put proj4string to the script since if any coords are available in the shapefile, it will be transported through the readOGR. ...
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1answer
120 views

encoding error between maptools and arcgis

I am having a trouble of encoding at writing shape file by maptools (0.8-34) of R by MacOSX and reading that by ArcMAP 10.2.1 in windows 8.1 through parallels desktop. Using an original shape file, I ...
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149 views

What is the most user friendly OSM route planning API?

I ran a workshop last week on GIS for Transport Applications. In Nick Bearman's tutorial (available from the previous link) we used Google's routing API (via ggmap) and CycleStreets.net routing ...
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228 views

How to set raster projection in R

I am new to R and grib files. library(raster) I have a "grd" file in and I am trying to set the coordinates to polar stereographic projection r <- raster("p190001.grd") # class : ...
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201 views

How to create geometric shapes in R? [closed]

I want to plot some geometrical shapes but I dont know what values to put in a vector so they can be plotted. How do you know what numbers should be inserted in a vector so they can create certain ...
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42 views

Rasterize gives weird image

ro<-readShapeSpatial("roads") ra<-readShapeSpatial("railways") co<-readShapeSpatial("LIE_adm0") u<-union(union(extent(ro),extent(ra)),extent(co)) rast<-raster(u,res=1) r1<-rasterize(...
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1answer
52 views

Shapefile One-to-Many Relationship in R

Is there any way to append a shapefile in a one-to-many relationship with its attributes that R can read? I understand the fix that resides in ArcInfo by creating through MakeQueryTable, but as this ...
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113 views

Put output of SAGA algorithm of Processing model in R script

I'm trying to combine the Variogram Cloud model of SAGA with an R script inside a Processing model. First, the R script is: ##Vector processing=group ##showplots ##Layer=table ##X=Field Layer ##Y=...
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267 views

How to get time-zones from latitude and longitude in raster?

I have a raster with longitudes and latitudes for the US with meteorological data (for about 100k grid points). I would like to get the time zone for each point in order to transform the time to local ...
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382 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. ...
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2answers
88 views

How to compute layer by layer after stack?

I have some rasters that I want to compute the moving average and then rewrite the rasters again. r1 <- r2 <- r3 <- r4 <- r5 <- r6 <- raster(nrows=10, ncols=10); r1 <- ...
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102 views

How to re-grid a raster using area-overlap weighted averaging?

I have two rasters r and r2 with different resolutions. I want to re-sample (re-grid) r2 to be the same as r using area-overlap weighted averaging:If an r grid cell is covered by more than 1 ...
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1answer
3k views

How to compute the number of none NA-values for each row?

I have a matrix(raster) that I am computing the the mean of each row in this raster as: library (raster) r <- raster(nrows=10, ncols=10);r <- setValues(r, 1:ncell(r)) # The x-values will ...
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576 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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3answers
4k 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 ...
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1answer
162 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 ...
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1answer
69 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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2answers
70 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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2answers
1k 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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1answer
262 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 rshs<-rasterize(shp_2,...
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2answers
176 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
215 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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2answers
3k views

How to convert a spatialpolygon to a SpatialPolygonsDataFrame 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$ratings=1 landc$ratings[landc$LANDUSE_ID==...
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1answer
234 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 ...
2
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2answers
183 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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1answer
151 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
341 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 colours....
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1answer
63 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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309 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
119 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
87 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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50 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
425 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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0answers
60 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
734 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 ...
5
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1answer
3k 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: library(...
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2answers
704 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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97 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 ...
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1answer
101 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
88 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
196 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
276 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 ...