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6
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1answer
781 views

Fixing orphaned holes in R

I'm trying to perform a union on a common field after merging two adjacent shapefiles. The shapefiles end up with at least one thin sliver of space between them. When I attempt a union I get the ...
2
votes
2answers
653 views

Convert shapefile with lists to data frame in R

I would like to ask some help for converting a shapefile to data frame. I downloaded data related to roads from Natural Earth. I imported the shapefile using shapefiles package like the following. ...
1
vote
1answer
193 views

How to convert raster to im object for point process model covariate in R

I am trying to convert a raster object to an .im object for use with a point process model in the spatstat package in R. I begin by creating the raster from a tiff file using the raster() package. No ...
1
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0answers
211 views

Using r, readShapeSpatial fails with simplified mapshaper.org shape

So I'm mapping out the postal regions of my country and it's an enormous, 5.4million row dataframe. I don't need every single little twist and turn of the boundries, so I was super excited to ...
1
vote
1answer
405 views

How to find highest kernel density point

I've been using spatstat to analyse point patterns in R. Here's an example to put this in context: library(spatstat) library(maptools) # to convert sp class to ppp Some point data: set.seed(1985) ...
0
votes
1answer
301 views

Subset netCDF based on last valid variable by level

I have a netCDF file (in this LINK) which contains monthly average values for 4 parameters at 11 different depth levels (0-200m). I would like to extract the monthly value for temperature "votemper" ...
2
votes
1answer
1k 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 ...
1
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2answers
563 views

Transforming and Projecting Shapefiles in R & ArcGIS for Desktop?

Perhaps this is an issue with one of my original data sources, but I've searched extensively to address this problem both through ArcGIS and R. I've got 2 separate sources of a county layer SourceA ...
3
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0answers
81 views

Resampling air temperature gridded data to sub-grid resolution

I'd like to obtain a 30-m resolution gridded dataset of air temperature from the ~1km gridded data of WorldClim, of Hijmans et al., 2005) for a mountainous region. The easiest procedure (I thought ...
1
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0answers
28 views

How to convert shapefiles to rasters? [duplicate]

I have my environmental variables such as elevation, soil, vegetation and others as shape-files. I want to use a raster command to upload them as tiff files for running a boosted regression tree in ...
4
votes
3answers
1k views

Per-pixel (statistical) calculations on a raster stack using GDAL

In R, it's relatively trivial to perform per pixel calculations based on a raster stack (e.g., get std.dev for each pixel on a 12 layer GeoTIFF). Unfortunately, the speed is less than desirable when ...
1
vote
1answer
274 views

How to open and plot Globcolour chlorophyll image in R?

Level 3 globcolour chlorophyll images (download from hermes) are in netCDF format. Those files can be imported via ncdf package to R 3.1. ch.nc = ...
0
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0answers
99 views

R PostGIS convert SpatialPolygon to PostGIS table

I've been having some success in scraping some webdata and converting it from HTML to spatial data as originally asked here: Parse PHP/HTML to shapefile or similar I've been using R to both fetch the ...
3
votes
2answers
212 views

How to iterate through features in a shapefile using R?

I am interested in iterating through a point shapefile to perform tasks on a point by point basis using R. In Python, this can be accomplished using the following workflow: import arcpy shp = ...
1
vote
1answer
233 views

Problem in creating neighbors, area and perimeter in spatial econometrics using R

I’m working on a spatial cross section model with R-programming-language. I’m running these codes which refers to anselin data (spatial_columbus) in spdep package. I found them from these links: ...
0
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0answers
92 views

Doing joint hypothesis test in spatial regression using R?

I'm doing estimation of spatial lag/error model using R package "spreg"/"spdep" but I cannot find any method to do anhypothesis test after regression. For example, I want to test whether two ...
5
votes
2answers
1k 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 ...
4
votes
1answer
207 views

Why covariance values are different in R and ArcGIS?

I've calculated covariance between 7 rasters using R and ArcGIS. It gives me different results. Each times covariance values from R are approximately 1.874 times higher than ArcGIS values. R - ...
7
votes
1answer
946 views

Route analysis in R based on the OSM transport network: possible?

I'm analysing the likely paths taken by commuters on their way to work, based on Census flow data, job density distributions and the transport network. At the moment I'm using pgRouting and the ...
8
votes
2answers
2k views

How to Find the Average Raster Value of an area defined by a shapefile using R?

I have a set of raster images which represent a specific month over the years, and I want to make a timeline of the average values of an area using a shapefile. How do I extract the values from the ...
1
vote
2answers
905 views

Avoiding R for windows gui front-end has stopped working error?

I am trying to load huge number of points (shape file) in R. But when I load it, the program displays following error message and just stops. "R for Windows GUI front-end has stopped working" My OS ...
1
vote
1answer
235 views

Adding a grid and selecting random cells from spatial polygon in r

I have a fairly similar question to this: Similar Question I am working with a map of Denmark or more a subset of a Denmark Map. This file comes from the Global administrative areas site GADM site ...
2
votes
2answers
625 views

Iterating polygons on a SpatialPolygonsDataFrame in R with readWKT

I have fetched some data (39 objects) from my PostGIS database and converted this data into a matrix: rs <- dbSendQuery(con, "SELECT ST_AsText(polygon_accumulation) AS ShapeWKT from ...
0
votes
1answer
132 views

How to get specific coordinate system to get arcGIS point shapefile in r?

I have a Point shapefile from arcGIS 10. I want to get it in r and also want to get it a specific predefined coordinate systen for my data. I can read the shapefile in R but summary in r Shows ...
0
votes
1answer
183 views

Extract single datapoint from netCDF file in R using ndcf

I'm trying to extract a single variable from a 3-dimensional netCDF file. [1] "file blah.nc has 3 dimensions:" [1] "longitude Size: 200" [1] "latitude Size: 100" [1] "time Size: 2000" [1] ...
5
votes
1answer
579 views

Convert ESRI Shapefile to Raster using R - biggest polygon area to raster cell value?

I want to create a raster from an ESRI shapefile. Multiple polygons may exist in one raster cell. If so, I want to assign the attribute variable which occupies the biggest area of the raster cell. ...
4
votes
2answers
194 views

Map location of unknown point with distances to two known points

I'm trying to develop a function in R that will locate a point (A) on a map given distances between that point A and two other points (B and C), for which exact coordinates are known. The problem I'm ...
2
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0answers
161 views

Moving point on OpenStreetMap route

Basically I generate random numbers in R language which are indeed times between bus arrivals. I need to simulate a moving point(a bus) in OpenStreetMap by using this generated numbers. I have read ...
1
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0answers
97 views

Rounding off coordinates in an SpatialPolygonDataFrame in R

EDIT AFTER COMMENTS After a comment of Whuber (Thank you!) I realized it will probably be most easy to incorporate a round(...) statement within my code to be able to work with less decimals. ...
0
votes
1answer
96 views

How to batch export using r.out.gdal command in GRASS

I created a list of files (NPPFILES) using g.mlist command in GRASS 7. Now I would like to export these files as .tiff files. I tried this command in GRASS prompt for files in $NPPFILES; do ...
2
votes
2answers
560 views

Create Raster file in R from Matrix and latlons

I could use some advice on how to create a Raster file in R with a Matrix of data points and the coordinates stored in a separate file. Both, data and coordinates come from a NetCDF file. I extracted ...
1
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0answers
78 views

Calculating surface and lines in 3D projection in R

For my internship research I am trying to compare the surfacearea and length of geometric shapes and lines in one coordinate system to another. I have a SpatialPolygonDataFrame in the European equal ...
1
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0answers
28 views

Calculating average raster values around set of points using ArcGIS for Desktop (or R)? [duplicate]

I have a 30-m elevation raster as well as a set of points that overlay the raster. For each point, I want to calculate the average elevation within a 5-km radius of the point. One way I was ...
2
votes
1answer
101 views

Is this a known issue in gaps between masked raster and spatial polygon in R with mask command?

This is my codes raster file: RAD polygon(shape): ws_sfc RAD.sub <- crop(RAD, extent(ws_sfc)) plot(RAD.sub) RAD.sub <- mask(RAD.sub, ws_sfc) plot(RAD.sub) plot(ws_sfc, add = TRUE) ...
0
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0answers
25 views

Kernel Density Analysis using R and ArcGis [duplicate]

I am doing some Kernel Density Estimations, and like everyone elese I face difficulties with setting the bandwidth to create georeferenced rasters. ArcGis (10.1) does it just fine, but it has no ...
1
vote
0answers
47 views

QGIS using different R lib

I am working with a colleague who is learning QGIS and has a question about the R plugin. His library path (.libPaths()) has two folders: "C:/Users/RDCERWAW/Documents/R/win-library/3.0" "C:/Program ...
0
votes
3answers
446 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 ...
2
votes
2answers
336 views

MODIS Level 1B batch process

I am a new MODIS Level 1B user. I have been using the MODIS Swath tool to process my images. However, I have over 1000 images to process. I was wondering if there a script available in IDL or R (very ...
2
votes
0answers
160 views

Using R to subtract the polygon area of one shp file from another

I'm looking to produce a map from two separate maps in R. My Maps files are as follows: ftp://ftp.cpc.ncep.noaa.gov/GIS/us_tempprcpfcst/610prcp_20140822.zip #Map1 ...
0
votes
1answer
93 views

going from hillshade to percent shaded (gdaldem)

I assumed hillshades output percent shaded (scaled to 255) at the given azimuth and altitude but this is incorrect. A flat raster at 80 degrees altitude has a maximum value of 251 instead of 255. How ...
1
vote
2answers
493 views

How to produce “SpatialPixelsDataFrame” from stacked RasterLayer?

How to produce "SpatialPixelsDataFrame" from staccked RasterLayer ? I have a stacked rasterlayer and I want to convert them to SpatialPixelsDataFrame. RasterLayer information is > RAD.all[[1]] ...
1
vote
1answer
185 views

create the postGIS table error No such driver: PostgreSQL

I'm trying to create the postGIS table with spatial features I can do it by: library(RPostgreSQL) library(spacetime) library(rgdal) dbname = "geodatabase" user = "postgres" password = "***" #password ...
1
vote
1answer
744 views

Step-by-step: How do I extract Raster values from Polygon overlay with Q-GIS or R?

I am writing my master thesis at the moment and am having the exact same problem as user Curley in this question: I first need to overlay a Corine 2006 raster with a polygon layer (2638 polygons). ...
0
votes
2answers
408 views

R -plot 12 images per plot or save 12 images per image file in R

Here is R script and my question is How can I plot 12 images per plot or save 12 images per image file because I have total 864 images. RAD1998 <- raster(paste(getwd(), "/1998bil ...
2
votes
1answer
237 views

Levelplot(RasterVis) two marginal plot scale?

How can I add/display scale to two marginal plot? RAD1998.all <- stack(list.ras) list.files <- mixedsort(list.files(paste(getwd(), "/1998bil/", sep = ""), full.names = F, pattern = ...
3
votes
2answers
707 views

How are kappa and overall accuracy related with respect to thematic raster data?

I recently calculated kappa (using confusionMatrix{caret} in R) between a thematic raster dataset at 1m spatial resolution and another at 30m spatial resolution. I was interested in quantifying the ...
2
votes
1answer
447 views

How to assign CRS to RasterLayer in R

I have a layer with coord. ref. : NA. How can I assign coord. ref. : +proj=longlat +datum=WGS84 +no_defs +ellps=WGS84 +towgs84=0,0,0 to coord. ref. : NA? class : RasterLayer dimensions : ...
7
votes
3answers
296 views

How to compare spatial patterns (crime cases vs population)?

I am looking for a way to statistically compare two spatial patterns in shape polygon data (not point pattern analysis). Let's say I have a city map divided in neighborhoods (barrios), in shape ...
2
votes
1answer
106 views

How to read ASTER metadata in IDL?

I'm trying to read many ASTER images (1B mainly) in IDL (I can try in R also). I'm used to work with Landsat, but the aster metadata is complicated. I write a code with a lots of conditional that can ...
3
votes
1answer
523 views

Max cell value from a stacked raster

How can I find a max cell value from a stacked raster. Rmax <- maxValue(RAD1998.all[[1]]) works fine but Rmax <- maxValue(RAD1998.all[[2]]) gives NA. Of course not in a stacked raster. ...