Statistical computing language and software environment.

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1answer
227 views

How to do geometric correction of remote sensing data in R?

My challenge is to replace most of the remote sensing commercial tools with R code (I'm teaching assistant at the University and I would like to move to open source R code to show the added values to ...
7
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1answer
193 views

Spatial Interpolation - defining a minimum value for agroup of points

I am doing spatial interpolation with a group of points. Some points have complete observation of events: for a period of 24 hours we have observed N events in each point. These points have N ...
4
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2answers
142 views

Problem overlapping shapefile and vector in R

I want to plot a shapefile over a raster file in R but I can't make them overlap perfectly: the raster appears to be rotated of few degrees counter-clockwise. Is it a problem with the projection? ...
0
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1answer
71 views

How can I export a point shapefile from ArcGIS to R

I am having several problems in exporting my point shapefile from ArcGIS 10 to R. I tried to save the shapefile as a CSV, but R reads all in one row; somebody in another question answered to use ...
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1answer
155 views

Convert multiple Shapefiles in Raster in R(and then plot it)

I'm trying to convert several shapefiles in rasters at the same time. I already was able to read the shapefiles by doing this: library(maptools) shps <- dir(getwd(), "*.shp") for (shp in shps) ...
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3answers
103 views

How to analyze and combine overlaping elevation maps into one?

I have 30 overlapping maps that contain tree density heights (measures between 1-100%) of a large area, and I need to get the highest point by pixel and create a new map with all these highest points ...
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145 views

Interpolate/disaggregate point values to an existing raster grid

I have several thousands of ASCII files whose names have the following format: data_"lat"_"long".mon (e.g. data_41.21875_-116.21875.mon). Each file represents one point in WGS84 projection and the ...
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1answer
288 views

Can't plot polygons with R and ggplot2

I am new to shapefiles so I maybe ask some stupid questions, sorry. I want to plot a map of my region, with colour filled polygons using R. I have downloaded municipal (lines) and province (polygons) ...
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1answer
227 views

How to get custom color palette in rasterVis plot3D in R?

I am trying to insert an RColorBrewer palette to visualize an elevation raster in R using the rasterVis function plot3D. The rasterVis reference document shows the following parameters: plot3D(x, ...
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2answers
889 views

Resources on using R in QGIS for R users?

This is a very basic question, but I'm having a heck of a time figuring it out because so much of the QGIS documentation is oriented toward use of the GUI. I want to be able to run R scripts in QGIS, ...
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110 views

Spatio-temporal prediction with KrigeST in R

I'm new in R and ST kriging, I've constructed a STFDF object with the first 4 hours historical data, and want to forecast the fifth hour data. By using krigeST in R, I've constructed vgm model. But ...
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1answer
188 views

Buffer analysis - use of surface area based on DEM

I have one problem and this is that I would like to create a buffer around point. This is simple with ArcMap using the buffer tool. But is it possible to create the buffer considering also the true ...
8
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2answers
301 views

Simple way to detect/select border polygons of a shapefile

I am looking for a simple way to detect/select border polygons of a shapefile. Border polygons are here polygons that are not completely surrounded by other polygons i.e. polygons located at the ...
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0answers
25 views

calculating mean and standard deviation for raster values using whole pixels within a polygon [duplicate]

i have a raster image and a corresponding shape file. i would like to calculate the statistics of the values within polygons which have a common attribute but only using pixels which are fully ...
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2answers
373 views

How to access each raster in a stack with a loop

I have a stack of rasters and I want to access each layer, combine each later with another file and finally export the resulting file as a csv file. Is there any way to do this with a loop? So far I ...
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0answers
303 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", ...
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1answer
695 views

Is it possible to create and run custom R scripts in QGIS 2.0?

I am new to QGIS and most of the tutorials I have found are for 1.x and the overhaul has me confused. I would like to create R scripts and run them in QGIS. I have read here that it's possible using ...
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0answers
220 views

R with ggplot2/ggmap - How to load a png image as a map

I am trying to find a workaround for ggmap's missing support of world maps (i.e. you can't create any maps that show latitudes > 80°, due to idiosyncrasies in the mapproj package). To a limited extend ...
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1answer
359 views

r openproj to plot in open street map in a different projection

I am very new to geographic data, so I am sorry for the stupidity of the question. I need to plot some data that are in this projection EUREF_FIN_TM35FIN Projection: Transverse_Mercator ...
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2answers
324 views

How to create random point in according polygon for each dataset entry in a list (with R)

I have an area divided into polygons, and a dataset of observations which has a common field with the polygon layer. I now would like to generate a random point for each dataset entry within the ...
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0answers
112 views

why readOGR() is not reading projection information from .spj - r

0 down vote favorite I successfully import a polygon shapefile with readOGR, however the information in the .prj file is not being imported. test class : SpatialPolygonsDataFrame nfeatures : 19407 ...
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1answer
213 views

Why does ManageR and rpy2 not work in QGIS (1.8.0-Lisboa)?

I have been trying to get R scripts to function and ManageR to work within QGIS (1.8.0-Lisboa). (Windows 7). Python2.7.5. Two problems indicated that R was not working in QGis. First - when I run an ...
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2answers
294 views

What is faster for geoprocessing (intersect) big shapefiles?

I have 200 Mb shapefiles of polylines downloaded from OSM. I've been working with QGIS 2.0 in Ubuntu 64 Bit 8 Gb RAM to make some geoprocessing tasks and it's taking 2 days for processing. Once I've ...
2
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1answer
290 views

How do I convert longitude & latitude to a 3d (geocentric x,y,z) coordinate?

I'm interested in finding the centroid of a point cloud. I understand that to do this I need to convert latitude and longitude values to 3d coordinates, average them and then convert the resulting ...
5
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1answer
815 views

Shortest distance from point to line (big dataset)

What is the best method to calculate the distance from the nearest road for a series of address points in QGIS, having a very big dataset? (QGIS 2.0.1, Win XP) I read the answers to previous similar ...
3
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1answer
450 views

Layer map plots on top of one another in R/ggplot2

I'm making a choropleth map in R/ggplot2. I have the colored part working just fine. This code p <- ggplot() + geom_map(data=c_1860, aes(map_id = GISJOIN, fill = AHL002), ...
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1answer
97 views

How to convert 'RasterBrick' object to 'im' object in R?

During script execution I need to convert 'RasterBrick' to 'im' object. Package 'geostatsp' is supposed to do this job: library(geostatsp) myraster = raster(matrix(1:100,10,10), ...
3
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1answer
137 views

Given a Lat and Lon, identify if the point is over land or ocean?

In R, what is the quickest way to identify if a point is over land or ocean? e.g. for: set.seed(0) lat <- runif(10, -80, 80) lon <- runif(10, -180, 180) points <- expand.grid(lat, lon) ...
3
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3answers
180 views

programmatically add field to shapefiles and insert shapefile name in every row of field

situation We have a folder containing 1 sub-folder for every participant in a study. The subfolders are named with the participants' ID, e.g., 1000, 1001, 1002, 1003. Every participant folder ...
5
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1answer
187 views

Legend of a raster map with categorical data

I would like to plot a raster containing 4 different values (1) with a categorical text legend describing the categories such as 2 but with colour boxes. I've tried using legend such as : legend( ...
4
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1answer
214 views

How to join data from NHGIS to make choropleth maps in R/ggplot2?

I have downloaded shapefiles of county/state boundaries and census data keyed to those shapefiles from the NHGIS. Both the shapefiles and the census data have a GISJOIN column to be used for merging ...
3
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1answer
298 views

How to link R script to Algotithm output in QGIS modeler?

I constructed a simple R script for QGIS modeler (.rsx) that calculates groupwise summary statistics of a vector layer table (sum by field "subject" and "FRC"). The script correctly works. When ...
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1answer
270 views

r.surf.contour in QGIS 2.0

I have a problem with r.surf.contour. I create a DTM with v.to.rast.attribute and then use the r.surf.contour and it works fine in QGIS 1.9 but with QGIS 2.0 doesn't work. I have a contour shapefile ...
3
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1answer
227 views

ggmap, ggimage… - Saving and loading maps in R

In my current R project I'm working with the ggmap package to download and display maps. What bothers me is that you need internet access to load maps from google etc. I'd like to load a map from the ...
3
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2answers
132 views

How to do regression analysis out-of-memory on a set of large rasters in R?

I am trying to do a regression analysis on a set of large rasters (254,004,000 cells each). Ultimately, I want to run something like the following (or a bit more complex, but let's start simple!): ...
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1answer
563 views

GDAL loads in Python, but not IPython (Linux)

I am trying my hardest to utilize the work of the good folks at the GeoDa center, but I cannot seem to get all of the components to load. GDAL, in particular, has been giving me some difficulty. The ...
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2answers
102 views

How can I fix a geoTiff with an incorrect CRS?

Trying to load and plot a raster (it's a DEM) in R, but having problems. Using R I read in a raster file: library(raster) dem <- raster("DEM_Victoria.tif") # >70 MB print(dem) class ...
2
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1answer
333 views

How to cluster Raster data

I have thousands of Raster data concerning the ice coverage at the pole at different times (days) over several years. Now I would like to perform a cluster analysis. I want to split the data into ...
9
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1answer
215 views

Proximity in space and time

I have some point data which represent daily lat-lon locations of an animal, with an associated timestamp. I would like to identify all points where STATIONARY = TRUE. A point qualifies as being ...
2
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2answers
189 views

MODIS calculations with non cloud contaminated pixels

I have 11 files showing 8day daytime LST temps in .tif format from MODIS. Is there any way to calculate the average 8day daytime temperature for march 2013 for example but using in the calculations ...
4
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2answers
404 views

Reduce the resolution of a shapefile in R (or QGIS if necessary)

I'm using shapefiles of history U.S. state boundaries from NHGIS to make maps in R. These shapefiles are much higher resolution than I need when making maps at the scale of the country: over 2 million ...
2
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0answers
200 views

Mapping Geocoded addresses onto Census shapefiles in R

I have a list of addresses that I have geocoded to get the corresponding longitude and latitude. > AddressDetail <- geocode(match_address) > coordinates(AddressDetail) <- c("lon", "lat") ...
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0answers
68 views

level of spatial aggregation of polygons

I am looking for a method that allows me to obtain the spatial aggregation of polygons for each cell of a grid with 10kmx10km resolution. In each cell (10kmx10km), I want to be able to consider that ...
2
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1answer
119 views

Interpolation with netcdf4 file

I have a netcdf4 data set that contains array and information about latitude and longitude which can be accessed with the following R command: ncvar_get(dataname, 'lon'); ncvar_get(dataname, 'lat'); ...
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2answers
111 views

Finding lines in point patterns?

I have a point pattern (see below) in which I assume to find "significant" lines of points. However, I did not find any method that is integrated in a GIS or in R that searches for such line pattern ...
4
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1answer
1k views

R - Plotting shapefile with geographical (raster) data

Over the last few days I have been trying to plot a shapefile over data loaded into a data.frame within R. It should be a view of radar precipitation with an overlay of the country borders from a ...
1
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1answer
105 views

Extract polyline of border between differing polygons

I have a shape file with polygons with an associated variable that can take different values. I would like to extract the borders between polygons of differing value (red and blue) as a polyline (dark ...
1
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1answer
47 views

How to return values of its order?

I have a matrix like this: 10 0.646519601 0 0.085929349 0.255477717 0.012073334 40 0.138403594 0 0.065979943 0.776693742 0.018922721 I want to keep the first column, and get rest ...
6
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1answer
379 views

Anyway to remove points outlying shape in ggplot2?

I am to map a plot of an area and then plot points over it (given by Easting and Northing). However, I found out that there are certain mistakes in the data entered for Easting and Northing resulting ...
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1answer
278 views

What is the equivalent of arcpy “Con” in QGIS and/or R raster-package?

I'm looking for an equivalent of the conditional expression "Con" from arcpy in an open source spatial analysis package? I'd prefer to use QGIS or R. To provide some additional detail, I need to ...