Statistical computing language and software environment.

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9
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150 views

Identifying overlapping time intervals with two more criteria in R?

I have to check birds observations made over a longer period for duplicate/overlapping entries. Observers from different points (A,B,C) made observations and marked them on paper maps. Those lines ...
9
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0answers
407 views

Multispectral image segmentation for natural-resources applications using R

R has the capacity for image segmentation, although all of the examples I have come across utilize a single band for the segmentation (example). I am interested in combining R's capacity for random ...
7
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0answers
676 views

How to get rpy2 for QGIS on OSX?

I am a new QGIS user, have installed QGIS on a Mac running Snow Leopard OSX 10.6.8 following all the instructions. QGIS seems to work well for everything other than when I boot up I get the message ...
5
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0answers
87 views

How to display wind data in R with the leaflet package

I have some data like this : longitude latitude speed direction 1 6.10722222 46.23639 4 360 2 6.95416667 43.54694 4 360 3 7.21472222 43.66556 ...
5
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0answers
48 views

rMaps choropleth with custom json

With R I want to make an animated choropleth map with the rMaps package and a custom map. I tried to follow the example of Diego Valle described here and to use the custom map info for Datamaps. ...
5
votes
0answers
61 views

Interpreting semivariogram high nugget

I made a semivariogram in R using package gstat, variogram() function. I want to see if there is spatial autocorrelation in the residuals of my model (species abundance as a function of habitat, ...
5
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0answers
735 views

Using stat_density2d with coord_map in ggplot2

In my example I am plotting a shapefile for all England & Wales, however I'm interested in the greater London area. If I allow ggplot to simply default and display the entire shapefile then the ...
4
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0answers
91 views

Using R to map matching GPS data?

I have a bunch of vehicles GPS data points, which consist of "timestamp, longitude, latitude, fuel consumption and distance" and the data is OSM (open street map) based. I want to match the data ...
4
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0answers
36 views

How to interpolate within defined boundaries of a deformed mesh using R?

My goal is to create an interpolation map of some output model results that are mapped on a deformed mesh (from a numerical simulation). The model results are in an x-y plane (representing ...
4
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0answers
48 views

Why does @data@values slot for RasterLayer only contain logical(0) and not the actual values?

Trying to get to the bottom of why, when I read in a raster of NDVI, the @data@values slot does not contain the actual values until I set them manually. For example: NDVI <- ...
4
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0answers
91 views

Resampling air temperature gridded data to sub-grid resolution

I'd like to obtain a 30-m resolution gridded dataset of air temperature from the ~1km gridded data of WorldClim, of Hijmans et al., 2005) for a mountainous region. The easiest procedure (I thought ...
3
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0answers
82 views

Interpreting Global Moran's I and should I krig?

I am trying to weigh up if kriging (or cokriging) the residual error from my model is a valid approach. My first step was to compute whether the error is spatially autocorrelated. I have done this ...
3
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0answers
87 views

Spatial weight matrix with boundary effects in R?

I need some help to finalize code for a spatial weight matrix that uses a nearest neighbor definition within regions, but does not allow neighbors from across a political border. For example, ...
3
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0answers
132 views

Subset two rasters with different extent and origin (and resolution) only where there are data in both in R

in R, I have two rasters with different extents and origins (and possibly even resolution). How to efficiently take the subset of each of them only where there are data in both of them? Here is a ...
3
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0answers
119 views

kriging of compositional data (grain size)

I have posted this already in the GEONet Forum but without any suggestions, now I am hoping for some feedback here: I have a problem concerning interpolation of compositional data of grain sizes. I ...
3
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0answers
46 views

How to set m parameter of clusterR function in R?

I want to manage a clustered computation on raster and thus use the "clusterR" function in R (package 'raster'). However, there's a tuning m parameter to set, but the only explanation about this ...
3
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0answers
184 views

How to calculate 90% confidence interval in a raster stack

I have a stack of grid files (23) in ASC format from a MODIS sensor and I need to calculate a 90% confidence interval, mean, min, etc, for each one in R, how can I do that? specially the interval. ...
3
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0answers
174 views

python equivalent of spatstat's spatial point process functions

Is there a free python package (i.e. PySAL?) that implements the standard summary statistics for spatial point processes, e.g. the F, G, J, and K functions? I'm happy to use R (i.e. spatstat) if ...
3
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0answers
776 views

Fortifying re-projected shapefile for ggplot2 in R

I have a shapefile of US county boundaries which I got from the NHGIS. I can load the file using the rgdal package and see information about it: library(rgdal) shp_1860 <- readOGR("shp", ...
3
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0answers
169 views

Can extracting raster values work in polygons' CRS without raster resampling?

I am trying to extract raster values using polygon layer with different CRS. Raster is in WGS84 (EPSG:4326) and the polygons in UTM (EPSG:23031). 1. If I want to work in the projection of the ...
3
votes
0answers
593 views

Novel ways of filling in missing values in a raster

I am looking for robust ways to fill in missing values in some rasters. They all have a single layer. Missing values consist of single pixels to medium sized patches. Rasters are around 1000 x 1000 ...
3
votes
0answers
337 views

How do I access layer attributes from within QGIS' manageR plugin?

This is probably a fairly basic question, but searches for manageR come up with a lot of noise, and there's no manageR tag. What I'd like to do is load the attributes from a particular field of a ...
2
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0answers
3 views

In QGIS 2.12 processing R scripts fails (plots remain blank) due to a wrong variable name - Is there a workaround?

I am trying to execute r scripts in 2.12. All of them fail. Plots remain blank. It seems that the variable "Layer[[Field]]" returns NULL: E.g: hist(Layer[[Field]],main=paste("Histogram ...
2
votes
0answers
17 views

Adding a custom color scale for a sp.points layer to levelplot() legend

I'm wondering how I can add a customized color palette that I used to display a sp.points layer in a call to levelplot (lattice plotting) in the rasterVis package in R. I used a function that Dave X ...
2
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0answers
29 views

R: Setting pop-ups dependent on zoom level using leaflet

I have data that I would like to group differently, depending on the zoom scale in an interactive map made using leaflet. I have expenditure data and I would like to show expenditure by lake at ...
2
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0answers
35 views

R Efficient Way to Resample, Crop, and Mask a Raster Image

Does anyone know an efficient way to resample an image? I am currently trying to crop a large image and clip 2 regions from a shape file. From this clipped image, I would like to increase the pixel ...
2
votes
0answers
26 views

Keys for merging US state/county ANSI's with GADM Unique identifiers?

I've got county-level data from USDA NASS, and I want to merge it with gridded climate data. A preliminary step is the associate the counties with the coordinates of their centroids. If I merge by ...
2
votes
0answers
43 views

How to pull a shapefile into R from PostGIS database (in Windows)?

I'm currently working on pulling data from a PostGIS database for the first time to map in R and need some help. The database contains a shapefile of countries/regions of the world. I am able to pull ...
2
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0answers
65 views

In R: Convert from WGS84 lat/long to UTM and back again to WGS84 lat/long

I am looking for a way in R to project WGS84 latitudes and longitudes to a UTM grid and then convert the UTM coordinates back to the WGS84 latitudes and longitudes. I have found a number of ways to ...
2
votes
0answers
49 views

Doing spatial regression using big data when Spatial weight matrix is too large for R?

I am currently doing an analysis on a quite huge data set - 250,000 polygons. I have figured out the general Moran's I for a linear model, but when I was trying to do a spatial lag or spatial error ...
2
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0answers
63 views

How to visualise change matrices over time

i've hit a bit of a tricky visualisation issue; I am quantifying some land use and land use change (LULUC) over a number of years. Typically, for data going from year to the next, a land change ...
2
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0answers
40 views

Raster memory usage in R

I am working with raster/brick data in R and running into memory issues. I am basically trying to use raster objects to perform some simple agent-based modeling, but the objects keep increasing in ...
2
votes
0answers
45 views

Efficiently calculate distance between raster patch edges

I have a binary raster which I've classified into patches using raster::clump. I now want to efficiently calculate the edge-to-edge, i.e. minimum, pairwise distance between patches. I am currently ...
2
votes
0answers
59 views

Merge Spatial polygons from shapefiles

I have downloaded the shapefiles from the following website: http://download.geofabrik.de/europe/france.html Each zip contains a "landuse" shapefile and I want to merge all of them in one single ...
2
votes
0answers
78 views

Get the intersection of two dataframes of coordinates R

I have two dataframes with geocodes. The first looks something like this: spoints<- data.frame(x=c(1,2,3,4,5,6),y=c(6,5,4,3,2,1)) spoints maps a country. My second data frame looks like this: ...
2
votes
0answers
52 views

From track+waypoints to elevation profile with waypoints

I have a track and waypoints (1) imported in QGIS. I want to calculate the closest point from every waypoint to the track (2). Then, I want a table with data that allows me to draw an elevation ...
2
votes
0answers
61 views

How to clip or erase a csv file with a non-rectangular shapefile?

I can clip a csv file with a ogr2ogr having 4 extents of a rectangular polygon. Is it possible to clip a csv file with a non rectangular shapefile?
2
votes
0answers
82 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 ...
2
votes
0answers
192 views

Computing Shannon-Weiner biodiversity index using QGis

I wonder if anybody has some experience in calculating biodiversity index (such as Shannon-Weiner) using QGis. I am also interested for similar experiences using R scripts within QGis. The analysis ...
2
votes
0answers
185 views

R Spatial: Trouble with disjointed polygon that has self-intersections

I have a shapefile which represents the areas of a city which have higher risks of flooding than others. This is a spatial polygon object however the polygon is disjoint and not connected. I also have ...
2
votes
0answers
43 views

How to measure similarity of approximately congruent polylines

My initial question was posted here. The answer of whuber provides a nice solution for the case when polylines are congruent. However, the problem is that my polylines are approximately congruent ...
2
votes
0answers
303 views

Calculate Euclidean distance to raster WITHIN multiple polygons

I am using ArcGIS 10.1 on a Windows x64 system. I am working in a study area where I have 360 000 locations of about 50 territorial animals. I have a shapefile containing 125 sometimes overlapping ...
2
votes
0answers
141 views

How to split a polygon into quadrants in R/Qgis?

I am solving the same problem as How to split a polygon into quadrants?, except that I am looking for a solution in R or QGis. So I have a polygon layer shapefile, which is unfortunatelly not exactly ...
2
votes
0answers
146 views

How to merge an excel file with a shapefile in r

I am new to mapping in R so my question might look trivial. I want to have a density map of US for number of phone calls for different areas. Each area includes some zip codes. I only have number of ...
2
votes
0answers
287 views

How to prevent cross-world lines in ggplot world map?

I'm having issues displaying 'great circles' paths and polygons in ggmap, an extension of ggplot2. Please enter the following code to replicate my issues: ...
2
votes
0answers
44 views

how to display the legend when the map contains external icons in R

I haven't found anything about the legend when the map contains icons external R (in png), is't possible to use the legend function or another function in R.
2
votes
0answers
78 views

does the census bureau provide clipped / water-bounded files as nice as certain cities?

this question says they do but when i compare what i can find in the cartographic boundary files section of the census bureau's gis page, they don't look as good as certain shapefiles provided by the ...
2
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0answers
155 views

Plotting Bare Soil Line on landsat data in RStudio?

I am using RStudio with landsat package for computing and plotting the Bare Soil Line (BSL) on landsat tif image running on my HP Pavilion i7 laptop. The codes for running the BSL() function is as ...
2
votes
0answers
212 views

Using R to subtract the polygon area of one shp file from another

I'm looking to produce a map from two separate maps in R. My Maps files are as follows: ftp://ftp.cpc.ncep.noaa.gov/GIS/us_tempprcpfcst/610prcp_20140822.zip #Map1 ...
2
votes
0answers
156 views

spatialpolygons heatmap in R - NAs in grey?

I have a spatial polygon data-frame and I am trying to plot a heatmap via spplot. It's a map of Europe and the values for the heatmap are in a column of the data-frame. Plotting it works fine but I ...