Statistical computing language and software environment.

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2
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0answers
70 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 ...
1
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3answers
124 views

How to access shapefile table in QGIS Modeler R scripts?

I need to develop .rsx scripts for QGIS 2.0.1 Modeler to do statistical elaborations on data tables of loaded vector layers. In this case I am not interested in accessing shapefile geometries, I'd ...
3
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2answers
116 views

Exporting Maps as PDFs in R

In R, trying to export choropleth maps with density and frequency histograms as legends; have had success exporting as an image but not as a pdf. Exporting as an image (.png) works well; the map, ...
1
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1answer
67 views

R: distance from one point to many polygons

OK so I have a spatial polygons data frame, and I have a point of interest. I want to add a row to the SPDF that contains the distance from the centroid of each polygon to this given point. How do I ...
0
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1answer
97 views

Units of gBuffer from rgeos package

I have this polygon: library(maptools); library(sp) setwd(system.file("shapes", package="maptools")) columbus <- readShapeSpatial("columbus.shp") proj4string(columbus) <- CRS("+proj=longlat ...
2
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2answers
61 views

How to extract values of one point dataset to second point dataset based on proximity using R?

I have to point shapefiles and would like to extract values from one point shapefile to another one based on some measure of proximity, i.e. for any given point in dataset x, extract the mean value ...
3
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1answer
89 views

plotting a SpatialPolygons object using lines() without lines connecting separate polygons

This is almost an extension of a question asked on stackoverflow (http://stackoverflow.com/questions/12196440/extract-feature-coordinates-from-spatialpolygons-and-other-sp-classes), so I'll use the ...
1
vote
1answer
119 views

Apply r.neighbours or Neighbourhood analysis (LecoS plugin for QGIS) to 3000 rasters

I need to apply r.neighbours or Neighbourhood analysis (QGIS plugin LecoS (or equivalent) to 3000 rasters and define a neighbourhood of 5 x 5 and calculate the mean. I suppose I need to create a ...
2
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2answers
217 views

Flow Accumulation in R

My apologies for such a general question. Is there an ArcGIS like implementation of Flow Accumulation for R? What I am trying to avoid: Using ArcGIS; Using Grass; Using RpyGEO (but will if need be) ...
1
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0answers
62 views

Write raster with its attribute table and symbology

I am classifying lots of rasters and I'd like to automate the legend creation and symbology displaying for easy manipulation. Here is the kind of raster I'm dealing with: library(raster) r <- ...
0
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1answer
137 views

Is there anyway to stack or merge .hdf files in R Studio?

I would like to be able to merge, mosaic, or stack several .hdf files. Does anyone know the package or library i should be looking for the tool to do this?
2
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3answers
326 views

How to get count of non-NA raster cells within polygon using R

I've been running into all sorts of issues using ArcGIS ZonalStats and thought R could be a great way. Saying that I'm fairly new to R, but got a coding background. The situation is that I have ...
5
votes
1answer
362 views

calculate {minimal} distance between polygons in R

I have calculated the surface area of species distributions (merging polygons from shapefiles), but since this area can be comprised of quite distanced polygons, I would like to calculate some measure ...
1
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2answers
142 views

convert data.frame with no lat-long info to a raster

coders, I need to read in a .txt file into R and later do some spatial analyses on it. I’m working in R. 3.0.2 on a Windows server. I load the following libraries (probably more than I need): ...
4
votes
1answer
158 views

Extract points from regular data.frame with coordinates based on SpatialPolygonsDataFrame in R

I have a regular data.frame called datos.merged class(datosmerged) [1] "data.frame" The last two columns are the corresponding geographical coordinates datosmerged[1,c(23,24)] XCOORD ...
1
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1answer
74 views

Convert point to grid: Numbers of cells differ

In R I am trying to aggregate points data to a grid. The data for the grid (G-Econ) comes as a csv-file. In this file each row represent a grid-cell at 1x1 degree resolution and the given ...
2
votes
1answer
180 views

Splitting strings into new rows, retaining geometry

UPDATED BELOW I have 9 shapefiles, each shapefile has 700,000+ rows and I have roughly 12 attribute fields in each shapefile. There are three attribute fields, common to every shapefile, that I am ...
2
votes
1answer
158 views

Access Shapefiles from PostgreSQL/Postgis in R

I successfully setup a connection to my PostgreSQL/PostGIS database on Ubuntu Server from my Laptop (Ubuntu 12.04). Therefore I installed RODBC in R to setup a connection and I made a correct entry ...
3
votes
1answer
154 views

Sample size for variogram modelling using the geoR package in R

I am trying to use the geoR package in R to model the variogram for a dataset of 15 000 sample points of bathymetry data. I intend to do a random split to create test (20%) and training samples (80% ...
2
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1answer
172 views

R or QGIS? Measuring elevation at points on DTM surface

Based on answers to this recent question I have been able to create natural looking digital terrain models using a combination of raster, rasterVis and rgl working on data held in ESRI ASCII grid ...
2
votes
2answers
121 views

Determine if points fall upstream or downstream from a point on a line (river)

I have a set of fish species occurrences (lat/long) as points and set of rivers as lines. The fish species can of course only occur in the rivers (and not on land). I would like to determine whether ...
3
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1answer
235 views

remove land area from marine region polygons

In my pursuit to merge multiple polygons for the purpose of calculating the surface area of marine species distributions, using shapefiles from Marineregions, I am now trying to remove potential land ...
0
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1answer
56 views

Can rgdal use an external GDAL installation?

The README for rgdal contains the following text: file.show(system.file("README", package="rgdal")) For additional drivers, users of the CRAN Windows and CRAN OSX binaries can either convert ...
1
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0answers
41 views

TPS and Kriging Cross-Validation

I am looking for existing package or functions that will allow me to cross-validate multiple outputs of Thin plate spline (TPS) and Kriging from the fields package. Does anyone know of any availabe ...
8
votes
3answers
218 views

R, rasterVis and RGL: how to prevent reflective surfaces?

I have been experimenting with digital terrain model files in ESRI ASCII grid raster format. Despite zero experience with this type of data I found it very easy to load into R, as per code below. The ...
5
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4answers
402 views

Calculating percent cover from shapefiles

I normally do not work with shapefiles, so I am a bit lost here. I have two shapefiles each with multiple objects. The first is a set of 32 polygons (each one is a plot). The second shapefile has ...
0
votes
1answer
141 views

Summarize values from a raster brick by latitude bands in R

I would like to sumarize (sum and/or mean) values from layers on a raster brick based on latitude bands (been using raster package). Been looking at the package documentation and didn't find a way to ...
2
votes
2answers
103 views

How to find the second highest value in a rasterStack in R

I have a rasterStack of rasters representing count data. I want to return a single raster whose values are the index of the raster with the second highest value for each cell. (I used which.max for ...
2
votes
1answer
110 views

Axis of rendered shape files not showing numbers that are latitude and longitude

I am using rgdal to render some shape file. The first is a set of building zones from NYC Open Data. The second is the NYC coast line from OSM. The Zone files seems to generally render an X axis ...
1
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0answers
65 views

Making spatial clusters by direct manipulation of raster pixel values using R

I think this is an overambitious million dollar question, but I'm always optimistic when I pose a question even though I feel like I left no stone unturned! I've processed a raster layer with pixel ...
0
votes
1answer
230 views

Scale parameter of the GetMap function within RgoogleMaps

Within the R library called "RgoogleMaps", there is a function called "GetMap" which is used to save a georeferenced image file. The library's manual suggest that the SCALE parameter supposed to be ...
1
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2answers
249 views

unionize intersections of merged polygons

[Updated quesion] I am using the following code to merged polygons from shapefiles for the purpose of calculating the surface area; library(maptools) library(rgdal) library(rgeos) #enter slots, ...
7
votes
3answers
296 views

R - How to sampleRandom() from large raster without NA values

I have a number of vary large rasters which need to be randomly sampled with the return value being a matrix of x, y, and value. The raster package sampleRandom(raster,n, na.rm=TRUE, xy=TRUE) will do ...
3
votes
2answers
239 views

Convert polyline shapefile to points 1m apart and add xy coords in R

I have a table with xy coordinates in R and the following packages loaded: spatstat, raster, rgdal, sp and zoo. I do know how to use this to make a point shapefile, a line shapefile that goes through ...
2
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2answers
278 views

Plotting a map of New Zealand with regional boundaries in R

I have been asked to make a map of New Zealand using R with regional boundaries. I need something exactly like this example of a map for Switzerland: ...
2
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2answers
204 views

How to use ggplot with Processing in QGIS 2.0?

I'm trying to use R scripts within QGIS thanks to Processing. There are some example scripts available and I achieved to plots different columns of the attribute table (with the plot built-in ...
1
vote
1answer
243 views

add unique IDs to mutiple polygons using loop or apply function

I want to add a unique ID (row number) for each polygon in a SpatialPolygonsDataFrame. I'm new at working with spatial data (and programming) so bear with me please. The goal is to merge all polygons ...
4
votes
2answers
75 views

towgs Definition for European Datum 1950

I am new to all things GIS so apologies for a basic questions. I am trying to specify the CRS of a climatic raster layer in R. It is an equal area projection based on Europe Equidistant Conic and the ...
0
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1answer
295 views

Calculate area covered by a particular raster layer within polygons in QGIS

I am trying to extract information on vegetation cover within a set radius of point locations (my sites). I have succeeded in creating a new vector layer of circles with a 5 km radius around my sites. ...
1
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2answers
660 views

Calculate distance in kilometers between two points

I have a few questions regarding the calculation of the distance between 2 postal codes. Take a look at the following code. ### # load the different packages we need ### require("rgdal") ...
0
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1answer
132 views

Update GEOS to 3.4

I want to use the rgeos function gDelaunayTriangulation (which requires GEOS 3.4) on my Mac, but when I load rgeos it says: > library(rgeos) rgeos version: 0.3-2, (SVN revision 413M) GEOS runtime ...
2
votes
1answer
68 views

R - Efficient way to segment rasters into sub-regions and sample… without using extract()

My question is: Is there a more efficient way to sample from a sub-region (defined by a shapefile read into a spatial object) of multiple rasters without having to use extract() for each region on ...
1
vote
2answers
240 views

Calculate a polygon around a point - and conver to WKT

The use case I have is this: I want to take points (in my case a data.frame of lat/long coordinates) and calculate a polygon around each point of a given radius (in km, miles, whatever). To be clear, ...
2
votes
0answers
112 views

Joining nearest neighbor small polygons using R

The figure shows a plot of numerous polygons (zoom in) made from a raster file by require(sp) require(raster) pol100 <- rasterToPolygons(r, fun=function(x){x==1}, dissolve=FALSE) There polygon ...
1
vote
1answer
838 views

How to make RASTER from irregular point data without interpolation

I was trying to make a raster image from an irregularly spaced point database. The data looks like- > head(s100_ras) x y z 1 267573.9 2633781 213.29545 2 262224.4 2633781 ...
3
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1answer
58 views

How to re-ID polygons with sapply instead of for loop

I have a line of code that renames the id's of polygons in a SpatialPolygonsDataFrame by directly manipulating the ID slot of the polygon. I'm a bit slow when it comes to sapply, having used for loops ...
3
votes
1answer
23 views

Equidistant projection for northern Delaware

I'm just getting started on a long-term project involving northern Delaware. Most of my distances will use great circle distances from the lat/lon, but for a few applications I'll wind up using ...
0
votes
1answer
113 views

R for loops in Geospatial modelling environment

I am using the isectpolypoly command in GME and would like to iterate over several polygons ("proj_0_ect0207", "proj_1_ect0207"). My code is as follows: for (i in 0:30) { ...
3
votes
2answers
127 views

Is there a way to speed up gIntersections for large spatial objects?

I'm attempting to perform a gIntersection of a big grid on a shapefile for country boundaries, so that I can calculate the % area of each grid cell that lies within the country. It takes a few seconds ...
4
votes
1answer
187 views

Loading a multipoint shapefile in R

This issue has only been raised in the community once, two years ago, to the best of my knowledge. I think it's high time to raise the issue again! readOGR, from the rgdal package, cannot handle ...