Statistical computing language and software environment.

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4
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1answer
233 views

Difference between gdalwarp and projectRaster

I am trying to project a Raster. In R there is the projectRaster() function to to this (below a fully reproducibly example) : # example Raster require(raster) r <- raster(xmn=-110, xmx=-90, ...
1
vote
1answer
185 views

Big performance difference reading shapefiles between QGIS and R

I'm trying to read the belgian landuse ESRI shapefile from geofabrik.de: http://download.geofabrik.de/europe/belgium.html In QGIS it's just a matter of seconds, but in R using the readOGR function ...
2
votes
1answer
326 views

Find intersections between spatial lines and points using R

This question assumes that I'm using R with the sp and rgdal packages installed. Now that I have a set of spatial segments of class SpatialLinesDataFrame (called 'segmentData') and a set of spatial ...
4
votes
1answer
79 views

How to find the distance from a point to a polygon, via another point, in R

I am trying to calculate the distances between a central point, and the edge of a polygon, along straight lines drawn between the central point and another set of points (where necessary extended ...
4
votes
1answer
139 views

Grid vs. Polygon Overlay in R gives different results than in QGIS

I have a shapefile of range polygons. Each colored set of polygons represents a different group of species/genera/whatever. I next overlay a 5x5 grid onto this map. And then use join attributes by ...
2
votes
1answer
163 views

How to find the coordinates of the intersection points between two SpatialLines objects (or SpatialLines and SpatialPolygon edges)

I am try to find the co-ordinates of points where SpatialLines cross the edge of a SpatialPolygon. I have searched and searched, but can only find results such as over which tell me which lines cross ...
0
votes
1answer
71 views

Extracting Data from Raster based on Aspect Raster file

I have 2 rasters, ones shows aspect and another shows date of snow thaw. I want to extract the date of snow melt based on values from the aspect raster. For example I want all the snow thaw dates from ...
0
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0answers
62 views

Different results of lagsarlm in R and GeoDa spatial lag model with identical weight matrix?

I ran a spatial lag regression model in R using spdep. Due to cross-validation of my results and data-size, I ran the same model in GeoDa but the resulting indices didn't match. My data(slot): ...
2
votes
1answer
405 views

Plotting species distribution on map in R

I'd like to plot the distribution of a species on a map of Switzerland, following this tutorial. library(maps) library(mapdata) map('worldHires', 'Switzerland', xlim=c(5, 12), ylim=c(45,48)) From ...
1
vote
1answer
77 views

Merge a table with a shapefile (not the same dimension)

I am trying to merge a table with a shape file using R. The shapefile's database is bigger than the table and I need to have null or zero values where the two data sets don't match. Table data no. ...
2
votes
1answer
922 views

How is R used with ArcGIS for Desktop? [duplicate]

How is R used with ArcGIS for Desktop? I have seen posts talking about combining rasters while using R. I have not had much experience with R so not 100% certain of its capabilities. I had ...
0
votes
1answer
121 views

iterate over spatial polygon data frame in R

I am trying to iterate over the rows of a spatial polygon data frame in R, but cannot figure out the right indexing. I don't want to select by attributes, but rather just iterate over the spatial ...
2
votes
1answer
338 views

Changing the extent of a Shape file in ArcMap for distrubution modelling in R

I am currently trying to create a species distribution model in R using maxent. The shape file I have is a map of an island. When viewed in ArcMap it has a set extent--in Lat and Long. I can ...
4
votes
1answer
198 views

Generate grid shapefile in R

I have the following shapefile of a 10x10 degree latitude/longitude grid that I created in QGIS. I can read it into R using the rgdal package. Grid<-readOGR(".","GridShapeFile") It has the ...
0
votes
2answers
71 views

Extracting a number of rows from a column in R

It's a shapefile that has a column with population. a$POP2001 It has 200 rows.I want to extract the settlements that contain less than 1000 residents, so i did this: s<-a[a$POP2001<1000,] ...
2
votes
1answer
686 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
90 views

Problem with regression kriging using the krige command in r

I want to perform regression kriging in R using gstat. I have a SpatialPointsDataFrame which is of this form: After I have run my glm model, in order to see which variables are statistically ...
0
votes
1answer
53 views

How to rasterize a shapefile in R? [duplicate]

I have several shapefiels that i have to turn into raster. Here's the coastline coastline<-readShapeSpatial("shp") r <- raster(ncols=90, nrows=45) jd<-rasterize(coastline,r) plot(jd) ...
0
votes
1answer
83 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") ...
2
votes
0answers
73 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
118 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: ...
1
vote
1answer
43 views

How to display the map within two longitude lines

I am new to GIS and I try to use the following code to display a pacific-centered world map. +proj=robin +lon_0=-198 +x_0=0 +y_0=0 +ellps=WGS84 +datum=WGS84 +units=m +no_defs However the map ...
0
votes
1answer
154 views

How to plot a shapefile with colors according to a column numbers in R?

reclass = function(x){ ifelse(x == 0, 10, ifelse(x > 0 & x <= 20, 0, NA)) } arch$ranks<-as.factor(unlist(lapply(arch$ranks,reclass)) arch.col = topo.colors(nlevels(arch$ranks)) ...
0
votes
0answers
21 views

Problem with passing ranks to different buffers

This issue is really troublesome.i have a SpatialPointsDataFrame which refers to a city.I needed to perform a join with a dbf in order to attach the population column which i did thanks to a couple of ...
1
vote
1answer
111 views

Getting range value from exponential variogram model

I am using vgm() from the gstat library in R: variogr <-vgm(sill,"Exp",range=range,nugget=0) output <-krige(...,model=variogr) As you can see I'm using fixed psill and range values. Before ...
0
votes
1answer
72 views

How to rank according to a distance in a shapefile using R?

I would like some help on the theory behind this. I have done this in GRASS easily but doing it in R is not the same. Here's the table with the info, there are more tables similar to that but refer ...
1
vote
1answer
117 views

Is it possible to zoom out a plot of a map in R?

Sometimes a plot looks zoomed in how to arrange that? i use the rgeos package mainly. When i do a buffer for example somewhere the plot tends to zoom in some part of the map which is not good since it ...
2
votes
1answer
117 views

How to join a dataframe with a dbf via a common column in R?

I have a SpatialPointsDataFrame with the data of a city and i want to join it with a dbf that contains the population via a common column that they have. How do i do that so the first one has the ...
3
votes
1answer
63 views

Association shape files to custom data in r

This is probably an obvious question. I have an Australia Shapefile (can be found here http://www.abs.gov.au/AUSSTATS/abs@.nsf/DetailsPage/1259.0.30.001July%202011?OpenDocument) and some custom data ...
0
votes
0answers
40 views

NetCDF4 Files: Missing Projection & Varying Dimensions (Multiple Files)

All, I hope you can shed some light on issues I've been having regarding NCEP Reanalysis-I netCDF-4 file format: First issue, Projection information is not stored on the downloads I obtained from ...
1
vote
1answer
103 views

R-Leaflet: Plotted points on wrong country

I am learning the leaflet package and am running into a snag. To learn the package I am using the Snow deaths dataset from the package HistData which contains historic Cholera deaths from an epidemic. ...
1
vote
0answers
195 views

way in R or Python to add image/video in map plot marker click popup/infowindow

I have many different (lat,long data) points of world associated with unique place names and corresponding each point specific image or video data. Now I want to create an html file where if user ...
2
votes
0answers
57 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 ...
0
votes
0answers
44 views

Calculating maximum mean temperature of the coldest month with a lists of rasters

I need calculate the maximum mean temperature of the coldest month. I need first select the coldest month in a list and then in this month determine the maximum temperature. I do this: Create the ...
1
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0answers
57 views

how to calculate distance in sub pixel mapping from Atkinson's paper?

Condition from atkindon's paper http://info.asprs.org/publications/pers/2005journal/july/2005_july_839-846.pdf for every sub-pixel the attractiveness Ai of a pixel i is predicted as a ...
6
votes
3answers
315 views

Waypoints with coordinates in R

I have a SpatialLineDataFrame with 20 observations of 4 variables (in WGS84). I want to create waypoints every 10 meters. Every waypoint will has the x y coordinates. I tried to do it manually like: ...
1
vote
0answers
160 views

Download Google maps data points

Is it possible to download google map data points? it would be usefull in order to gather in datasets all the restaurants in a dataset for example. I am using R but suggestions is other programs are ...
5
votes
3answers
387 views

Save and load maps for ggmap to use without internet access

I would like to use the ggmap package to download and display maps. Unfortunately I have some firewall restrictions preventing R from accessing the internet directly. The error I get from get_map is ...
5
votes
1answer
2k 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 ...
1
vote
0answers
40 views

Modelling zero-inflated spatially autocorrelated data with extreme values

I have spatially explicit data (above; Longitude, Latitude) with measurements on a random variable (z). This data was not collected in a random or systematic fashion, but instead was recorded ...
0
votes
1answer
181 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 : ...
1
vote
1answer
122 views

Convert shapefile to WGS84 [duplicate]

I have a shapefile with shapelength and shapearea, and would like to convert to WGS84 to use with ggmap. Eventually, I would like to get plot google map of individual regions of the shapefile, and ...
1
vote
0answers
22 views

weighting scheme of gstat for fitting models to variograms

I use R and the gstat package to construct variograms of temperature, and I would like to ask If anyone knows what weighting scheme does the gstat package use to fit a model to the sample variogram?
0
votes
0answers
55 views

Why does R(gdal) mangle data when converting to geojson?

I've encountered issues with projections in .geojson files created by rgdal, but I never thought it would destroy my data, until I tried this (reproducible example): ...
0
votes
1answer
160 views

Add Points shp attributes to Polygon shp by Point location (as Spatial Join in ArcGIS)

I have a set of points in .shp (ESRI, available here: http://ulozto.cz/xGqRVFrR/voronoi-zip). I would like to calculate Voronoi tesselation from the points, thus create polygons. So far, so good. ...
1
vote
0answers
70 views

rgdal with multiple Feature Datasets in R

I am trying to read shapefiles contained within a geodatabase file (.gdb) into R. The .gdb contains two Feature Datasets with multiple Feature Classes within each. The problem is only one of the two ...
9
votes
2answers
3k views

How to get the second nearest neighbor between two point patterns in R?

Is there a way to get the distances for the second nearest neighbor between two point patterns in R? The spatstat package has a function called nncross but it only applies to the nearest neighbors ...
14
votes
3answers
753 views

How to determine if trees within forest gaps are clustered?

The attached dataset shows approximately 6000 saplings in approximately 50 variable sized forest gaps. I am interested in learning how these saplings are growing within their respective gaps (i.e. ...
3
votes
1answer
559 views

R - How to “smooth” a raster map

I am trying to create a map from raster data. The file came from a crop model, with resolution of 0.5 degree. Even when I disaggregate it (i.e. increase spatial resolution), the map looks really ...
1
vote
1answer
183 views

unsupervised random forest classification in R

I want to compute an unsupervised random forest classification out of a raster stack in R. The raster stack represents the same extent in different spectral bands and as a result I want to obtain an ...