Statistical computing language and software environment.

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8
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2answers
3k views

Removing rows in shapefile in R

I've imported a shapefile into R, and joined it to a table. My shapefile contains all the census ids, while my table only contains selected census ids. I'm now trying delete all the rows didn't get a ...
8
votes
1answer
9k views

Converting a polygon into a raster using R

I'm trying to convert a shapefile into a raster within R. My approach is to read in the raster as follows: library(rgdal) # Loads SP package by default demo <- readOGR('F:/data/', 'shapefile') # ...
8
votes
6answers
9k views

how to overlay a polygon over SpatialPointsDataFrame and preserving the SPDF data?

I have a SpatialPointsDataFrame with some additional data. I would like to extract those points inside a polygon and at the same time, preserve SPDF object and its corresponding data. So far I've ...
3
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1answer
570 views

Join spatial polygons by code in R

I am in the process of creating a spatial polygon map for the Valencia region in Spain. I asked the question in StackOverflow (http://stackoverflow.com/q/19791210/709777) and could produce the map. ...
2
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2answers
2k views

How to create a map with states by attribute value?

I'm using Qgis, but I am quite familiar with R and python. So I could use any of these. I want a map of mexico but want to color the stats according to a certain variable. It goes from 0 to 100. So ...
11
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2answers
4k views

Aggregating points to grid using R

I have a question with regard to spatial aggregation in R. What I am trying to do is aggregate a point dataset to a grid. I am unsure however how to do this as I have little experience with this sort ...
6
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2answers
2k views

creating a raster of the residuals of a regression between two rasters

I am trying to create a raster of the residuals of a regression between two rasters. i.e. I would like to carry out a regression of one raster against another of the same extent and plot the residual ...
9
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3answers
5k views

Reading File Geodatabase using R?

File geodatabase (fgdb) includes numerous file geodatabase tables. As far as I know they exist as dbf files, but are within a Database.gdb. In ArcCatalog, the file pathway resembles ...
8
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3answers
564 views

Fastest way to convert big raster to polyline using R or Python?

I have a big raster file (129600 by 64800 pixel) with global water bodies (1 bit values 0 and 1) and try to extract ocean and inland water shorelines. I've tried with ArcGIS and QGIS to convert from ...
8
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2answers
4k views

Clip Spatial object to bounding box in R

Given a Spatial object in R, how do I clip all of its elements to lie within a bounding box? There are two things I'd like to do (ideally I'd know how to do both, but either is an acceptable solution ...
6
votes
2answers
3k 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 ...
6
votes
1answer
610 views

How to 'reverse clip' (erase) in R

A reverse clip saves only the part of your spatial object that is outside the bounds of another object, as opposed to a regular clip which saves the parts that are inside the other object. Here's how ...
2
votes
1answer
131 views

Incorporating terrain data to predict canopy cover using randomForest in R

This is a subjective question. Thank you bearing with me. I have a 5.8 m resolution satellite image (LISS IV by IRS-P6, in bands 4, 3 and 2) of a densely forested region in the Eastern Himalayas. My ...
2
votes
1answer
2k views

Counts the number of points in a polygon in R

I have two classes sharing the same CRS (Latitute and Longitude): bolognaQuartieriMap: a SpatialPolygonDataFrame containing data of a city boroughts. crashPoints: a SpatialPointsDataFrame containing ...
7
votes
3answers
668 views

Making county-level shapefile from set of points at 30 x30 km spacing using ArcGIS for Desktop?

I have a data set in csv form, like: latitude, longitude, value -45, 45, 10 .... I would like to calculate county level means from these data, using either ArcGIS or R+grass. I have the ArcGIS USA ...
6
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2answers
6k 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 ...
4
votes
1answer
492 views

How can I parse modis MOD13Q1 quality layers in R?

I'd like to parse MOD13Q1 VI quality layers in R. My original code must have been incorrect, because it gave lots of "deep ocean" flags in the middle of Brazil. After the changes suggested by ...
3
votes
1answer
144 views

Processing large amounts of Rasters in R

I have 6500 processed and clipped rasters that indicate snow levels on a daily basis in the northern hemisphere. I need to create a raster that represents a sum of the snow for the season. The winter ...
3
votes
1answer
394 views

How to create randomly points within polygons for each row of a dataframe matching a Polygon ID with R

My question is similar to this post, but because there are no "perfect" answer and above all no reproducible example I open this question. I have a "SpatialPolygonsDataFrame" and a data frame. Both ...
3
votes
1answer
565 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 ...
3
votes
3answers
3k views

Setting “R Folder” Path in QGIS Sextante

I have installed R via the R-Project website. I have QGIS installed via OSGEO4W (currently 1.9.0 Master), and have Sextante plugin installed and working with GRASS and SAGA providers. I am now trying ...
2
votes
1answer
537 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 ...
1
vote
1answer
240 views

Using Loop for calculating NDVI

I am using MOD09Q1 now and I would like to calculating NDVI whole year data. One year, I have 46 band 1 images and 46 band 2 images. list.files I creating list of band 1 and list of band 2. ...
0
votes
1answer
203 views

Spatial Join in R

I'm fairly new to using R for spatial work so bear with me. I have found questions similar to this but nothing that answers this question specifically enough for me to implement it. I have point data ...
0
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3answers
717 views

Import shapefiles on my postgis table using R

Using R, I would like to import shapefiles that are in a directory on a geometric table i have on postgresql / postgis. What is the instruction that allows me to do it? EDIT: here is my code to ...
0
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1answer
1k 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 ...
9
votes
1answer
714 views

Kriging on GRASS+R - cannot allocate vector of size 146.5 Mb

I'm trying to do a groundwater elevation map with an Ordinary Kriging on R, but always resulting on the lack of memory cannot allocate vector of size 146.5 Mb allocation (windows xp 32bit). ...
5
votes
3answers
3k views

How can I find out how to convert this point to lat lon?

I have received a shapefile with measurement points to be analyzed, but no matter how I try, I can't find how to convert to lat lon. I suppose it would be good to know the projection but when I look ...
4
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2answers
275 views

Alternatives of spTransform?

Let's say that we have a shapefile with a certain projection. s<-readOGR(dsn=".",layer="Spain") We also have the airports of Spain as points in another projection. ...
3
votes
2answers
430 views

Display two-dimensional color gradient for two different quantities

I have two overlapping raster layers. One contains quantity A from 0 to 100, and the other contains quantity B from 0 to 100. I'd like to create a map displaying both sets of data at once based on a ...
2
votes
1answer
65 views

Error in In predict.gstat in R

I am trying to do kriging by gstat pcakge through R. Here is my Code: krg<-krige(var ~ 1,data,grid,model=vgm,nmax=30) But each time I recive this warning: 1: In predict.gstat(g, newdata = ...
2
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1answer
199 views

R-bridge minimum requirement

The new R-bridge, unveiled at uc2015, has a dependency on ArcGIS 10.3.1. Has anybody tested it with older version of ArcGIS Desktop? I need to know why it depends on 10.3.1. I need to run it on ...
2
votes
1answer
845 views

How to reproject a raster from lat/lon to UTM in R?

i have to turn it into a UTM in order to make the buffer functional. wets<-readOGR(dsn=".",layer="shapefile") r.raster <- raster() extent(r.raster) <- extent(wets) res(r.raster) <- 100 ...
2
votes
1answer
673 views

Distance to nearest point for every point same SpatialPointsDataFrame in R

I have a SpatialPointsDataFrame that I'm working with in R. I want to add a new vector to the dataframe that contains, for every point, the distance to the nearest other point in the ...
2
votes
1answer
4k views

Converting decimal degrees units to km in R?

I am trying to figure out how I can transform my unit of length from decimal degree to km when I import the following simple ArcGIS polygon shape. Ultimately, I would like to have this information ...
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0answers
22 views

writeOGR R and add an icon symbol [closed]

I am wondering if there is a way to add an icon symbol to the R code I am using to export data in GPX format. In the navigation program I import the GPX file into all of the of coordinates are ...
1
vote
2answers
61 views

Create a raster with ranges from another raster

I have a raster that contains values ranging from 1-180. I am looking for a way to create a new raster where if the values of a cell in the original raster is between 1-10 the new raster cell gets the ...
0
votes
1answer
122 views

When aggregating points by polygons with sp::over function, how do I include attribute data from both the points and polygons? [duplicate]

Data: Zipped ea.ml1 shapefile can be found here, and the country outline can be downloaded here at the GADM site. I've been using the Ethiopia ESRI shapefile. Branch locations are here. I have a ...
0
votes
1answer
94 views

How to rasterize a vector dataset in R?

I would like to compare vector vs raster data. So i try to fix a problem using both ways. I made it in vector first : coastline<-readShapeSpatial("shp") wets<-readShapeSpatial("shp") ...
0
votes
2answers
409 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 ...
43
votes
9answers
18k views

Tutorials to handle spatial data in R?

Does anyone know some good tutorials to handle spatial data in R? I know that there are some packages like rgdal and maptools but I haven't actually found usefull tutorials to get in touch with the ...
24
votes
4answers
8k views

How to efficiently read a kml file into R

I'm working with huge .kml files (up to 10 Gb) and need an efficient way to read them into R. Until now I've been converting them to shapefiles via QGIS and then back into R with readShapePoly and ...
18
votes
1answer
2k views

Robust alternatives to Moran's I

Moran’s I, a measure of spatial autocorrelation, is not a particularly robust statistic (it can be sensitive to skewed distributions of the spatial data attributes). What are some more robust ...
21
votes
6answers
14k views

How to cluster spatial data in R?

I am very new to R. I have bunch of data points with latitude and longitude. I want to use R to cluster them based on their distance. I have already taken a look at this page and tried clustTool ...
14
votes
3answers
787 views

Ecological geospatial conundrum

I am looking for a different, more elegant solution to a spatial statistics problem. Raw data consists of an x-y coordinate for each individual tree (i.e. converted to a point .shp file). Although ...
13
votes
2answers
3k views

How to speed up the plotting of polygons in R?

I want to plot the country borders of North America over a raster image depicting some variable and then overlay contours on top of the plot using R. I have been successful in doing this using base ...
13
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1answer
10k views

Raster legend in R: how to colour specific values?

I have an elevation model plotted in R r <- raster("example.dem") plot(r, col = topo.colors(20)) Some of the values are below sea level (0), and I'd like to have those display in red. How can ...
10
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1answer
27k views

find the centroid of a cluster of points

While searching the web, solutions for finding centroids of polygons come up rather often. What I'm interested in is finding a centroid of a cluster of points. A weighted mean of sorts. I would ...
10
votes
4answers
2k views

Problems with NA values when reading .DEM file with R 'raster' package in Windows

I am trying to read a raster file in a .DEM format on windows using the 'raster' package in R. I get problems with NA values, when loading the data into R in Windows 7, but I do not have the problem ...
9
votes
1answer
4k views

How can I use fortify() to create a filtered R data frame from a shape file?

I am in the process of building a ggplot choropleth map of population in administrative areas in Wales. I have downloaded the Boundary-Line data from the Ordnance Survey and extracted what seems to be ...