Statistical computing language and software environment.

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How to build a function that extracts information from a set of polygons at multiple points in R

I am new to R, and trying to build a simple function that calculates an average (mean) of Sum_MVKT extracted from a set of predefined point locations. For this, I have two shapefiles named ...
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2answers
372 views

How to read and write tiff image and locate pixels and bands of images in R

I'm new in R I want to know how to read and write tiff format image in R and how to use R to locate pixels and bands of images My environment is in Windows when I try to read tiff image it shows ...
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1answer
144 views

Package getcartr Installation Problems

I want to build a cartogram by following this tutorial. The first thing I did, I spent the R-R-3.1.1 version 3.1.2 then I did the following: library(devtools); ...
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2answers
342 views

buffer and union in R without reducing to a multi-polygon

I would like to perform a spatial overlay to identify the polygon within which a set of points fall. However I first want to buffer and dissolve the polygons, such that points falling anywhere within ...
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3answers
310 views

Save rasters created by loop operation to different directory?

I have a set of rasters. I crop them all using FOR loop. Then, I want to save new-created rasters in new directory, not in my actual directory. For one raster it is easy: writeRaster(raster1, ...
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2answers
189 views

Remove clumps of pixels in R

I would like to remove isolated pixels (or clumps of pixels <9) from my raster image. library(raster) # create some raster data r <- raster(ncols=12, nrows=12) set.seed(0) r[] <- ...
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0answers
32 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 ...
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3answers
284 views

How to measure similarity of SpatialLines objects

I created two SpatialLines objects in R: . These objects were created this way: library(sp) xy <- cbind(x,y) xy.sp = sp::SpatialPoints(xy) spl1 <- sp::SpatialLines(list(Lines(Line(xy.sp), ...
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1answer
64 views

Add a single column to multiple SHP

I was looking for a way to add a new column to several shp (simple polygons) at the same time. I don't know much about batch command. This new attribute is also a little bit tricky : I need to ...
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2answers
49 views

Getting raster values on grid nodes

I have my raster layers of Digital Elevation Model, aspect, slope and curvature for a certain region. In this region I want to apply a grid with a certain spacing in its nodes, and then get the ...
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2answers
145 views

System call gdal function in R on Mac

Hopefully someone can help me figure this issue out. I am trying to system call gdal functions inside of R using the system / system2 functions. Here is an example of the code: > system("gdalinfo ...
2
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1answer
145 views

How to write every raster from a list of rasters?

I have created a list of rasters - "norm" and run a several loops. Now I would like to write every created raster from "norm" (containing 1 layer) into one raster, having its specific name. # I can ...
2
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1answer
558 views

r - increase speed of crop, mask, & extract raster by many polygons

I'm extracting the area and percent cover of different land use types from a raster based on several thousand polygon boundaries. I've found that the extract function works much faster if I iterate ...
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57 views

Using the accCost() function in R: questions regarding the transition layer

I am trying to use the accCost() function from the gdistance package in R. I load my cost raster using the raster()function from the raster package. According to the documentation, I need first to ...
4
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1answer
523 views

How to import multiple stacked raster images in R?

I have (I suppose) wery easy and silly question but I can´t really find my answer... I would like to import all multiple mosaic rasters (each mosaic is composed by 7 layers) from indicated folder into ...
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68 views

How to run GAM with raster package?

When I am using the raster package to predict a surface probability map of species distribution using the following functions in R, the following error occurrs: CA132122200=raster("F:/CBG ...
2
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1answer
147 views

Incomplete intersection area using gIntersection in R

I have two SpatialPolygonsDataFrame, one of them is the deforested area in the Amazon and the other is the city of Vila Rica, which is in the same region. I would like to calculate the total ...
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142 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
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1answer
84 views

Whats the best way to convert this tab data to a raster?

I have some grid data that is stored in a xls file. The rows are lattitude and the columns are longitude values in decimal degrees (see image). What would be a quick and efficient way to convert ...
2
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1answer
29 views

Converting character attribute to numeric attribute

I am following the very simple code found in this question Converting shapefile to raster: Character attributes to create a new numeric variable based on a factor. My proble is that the new numeric ...
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0answers
77 views

gpclib package in R

I'm trying to do a locoh run on R version 3.1.2. Since the gpclib package is depreciated, I've installed and loaded rgeos (the package gpclib has been replaced with). However, the locoh run can still ...
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28 views

KDE looping in GME

I can not get this for loop to run in GME because i is being changed to 1 and , out is not recognized: wd <- "C:\Users\name\Desktop\KDE\2011\"; for (i in 1:15) { ...
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1answer
75 views

GME: could not open input point data source

I can not get this for loop to run in GME because i is being changed to 1 and , out is not recognized: wd <- "C:\Users\name\Desktop\KDE\2011\"; for (i in 1:15) { ...
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1answer
100 views

For loops + boxplot for raster

I have several Rasterstacks (b1_mask, b2_mask,...) of several layers representing only a determined pixel-intensity range. (So point "A" in some layers is "NA" - in others a "value" of that certain ...
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2answers
75 views

Create lines from polygon borders with polygons attributes

I have a shapefile of polygons that border each other perfectly, each with a numerical attriubte. I'd to create a shapefile of lines, where every line is created from the border between two polygons, ...
0
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1answer
51 views

Extent from Centroids, Projection, and Resolution?

I have a file that defines a raster, although all the metadata was lost. I know the lat/long coordinates of the grid centroids, and that the grid is in a Mercator projection with a 1/12deg equatorial ...
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47 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 ...
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121 views

How to extract percentage of land cover from a raster according to multiple shapefiles?

I have a raster map that represents land cover of a region, and different shapefiles (total 120) in the same region. I want to know the percentage of every land cover for each shapefile. For example, ...
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66 views

Identify nearest neighbor in grid in R (spatial)

I would like to create a square grid and identify the grid cells that border a set of other grid cell for which a binary variable takes a 1. In the following example, I would like to generate a vector ...
0
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1answer
93 views

R using fortify to project shapefile on google map gives wrong results

I have a shapefile that looks like this > str(FieldsMap) Formal class 'SpatialPolygonsDataFrame' [package "sp"] with 5 slots ..@ data :'data.frame': 3 obs. of 2 variables: .. ..$ id : ...
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1answer
105 views

Export to images subsets of Spatial Points Data Frame

I have a csv file, which I converted it to Spatial Points Data Frame. And I want to split the spatial data and export each map to a jpg file. I did the following: SB <- read.csv("SB_040914.csv", ...
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3answers
668 views

Unable to run R in QGIS 2.6 - rgdal unavailable for R 3.1

I'm attempting to use R within QGIS2.6 on OSX Mavericks but cannot get R to run because rgdal is not available as binary for R3.1.2 (see QGIS log output from R execution console below). I have ...
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66 views

Spatial regression lag on dependent and independent variables in R

I have a SpatialPolygonsDataFrame with summarize data about some regions. How can I make a spatial regression with lag both in the independents and dependent variables in R, like this: Where y is ...
2
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2answers
221 views

In ESRI ArcGIS, is there an equivalent to the RStudio Console Windows?

UPDATED I know ESRI provides scripting capacity, via the Python window, but I've had a hard time with it. Making the jump from the Field calculator to the Python window was too much to me. Trying to ...
2
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2answers
162 views

Is there an R equivalent of NEAR in ESRI ArcGIS?

I have 54 points in one data set A I have 300+ data points in a dataset B. I wish to find the distance for each point in dataset-set B, to points in dataset A. Nearest Neighbor packages appear to ...
3
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1answer
92 views

comparing and finding inaccuracies in two raster layers

I have two raster layers with urban cells and rural cells. I used an overlay function to compare these two raster layers and see the differences. Before overlaying I gave urban cell the value 1 and ...
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2answers
90 views

projection differences in R

I am trying to reproject some climate data that I downloaded from http://gdo-dcp.ucllnl.org/downscaled_cmip_projections/dcpInterface.html#Welcomein The BCSD-CMIP5 data is found under the tab ...
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0answers
83 views

How to define the output raster resolution when rasterizing a vector?

I have a vector file which I want to rasterize and adjust its resolution to the reference map, in QGIS. I tried spatial_sync_raster function in R to set all the rasters into the same resolution as ...
1
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1answer
52 views

gTouches error without geometry error?

I have a map showing administrative boundaries (available here). I've loaded it into R and have attempted to run gTouches (from rgeos) to determine which areas are adjacent to which, but receive an ...
2
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2answers
482 views

combine rasters into single raster with multiple field values in R

I have several raster brick objects that I would like to combine into one raster with multiple field values for each cell, but I am not sure how to do this in R. For example, let's say I have two ...
7
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3answers
238 views

Best way to make a fake hillslope?

Anyone ever have to make a fake hill slope? or a fake digital elevation model (DEM)? What are the best methods for doing so? For more specifics, suppose I wanted to make a fake hill slope, that was ...
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86 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 ...
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148 views

Creating the Regions based on spatial clusters

I need to create areas for my shapefiles for spatial analysis for each. So I have a number of stations and I created 5 clusters based on the distance. code: Al <- ...
2
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0answers
173 views

Raster to polygon using R [closed]

I am trying to convert a raster object to a polygon object using R but I am running into some problems using my Windows 7 machine. I originally tried to use rasterToPolygons (package: raster) but it ...
2
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0answers
86 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 ...
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44 views

Unexpected Moran's I value in R using a chessboard example

I'm running into unexpected values for Moran's I when using the Moran.I function in the R library "ape". My understanding is that a chessboard is an example of perfect negative spatial ...
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3answers
338 views

From polygon to continuous measure of diversity?

First of all; I have tried to find a similar question, without success. Maybe it's because I'm quite new to GIS and I don't really know what exactly I'm looking for. If someone points me to a similar ...
5
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1answer
450 views

Convert coordinates from readShapePoly in R to long-lat coordinates

I'm trying to find some centroids of a shapefile for Danish municipalities and afterwards find the driving time between them. I use R's readShapePoly function from maptools combined with the ...
2
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1answer
77 views

clustering map (North, Centre, South) in R

I am looking for a method to partition map in 3 groups (North, Centre, South) like this: how to do this in R please stations.txt Code : Al <- shapefile("DZA_adm/DZA_adm0.shp") # read in ascii ...
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0answers
105 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 ...