Statistical computing language and software environment.
7
votes
2answers
663 views
Is it possible to run an R script on a layer in QGIS?
I'd like to run an R script on a layer loaded in QGIS (to rotate a set of points created there using the Vector:Research Tools:Regular Points tool). I thought ManageR might work but cannot get it ...
4
votes
1answer
336 views
Simulation envelopes and significance levels
Many spatial analysis packages provide Monte Carlo techniques to simulate upper and lower “envelopes” for a summary statistic as a function of distance (e.g. K-function, nearest neighbor, etc…). ...
7
votes
4answers
3k views
How can I export raster data from Arcmap to an R *.grd file format?
I want to work with raster data in R, but I have problems exporting my raster dataset from ArcMap. By "export data"/GRID I get a file with an *.aux extension. What I need is *.grd.
Can anybody help ...
7
votes
1answer
225 views
How do I randomly alter a raster map of habitat types?
I have a raster of habitat types for a specific area in Scotland. I need to create future habitat scenarios with changes in habitat to assess the population viability of a bird species.
For example, ...
3
votes
4answers
660 views
relationship between sp package in R; mapwindow; ArcGIS/Quantum GIS
I am using ArcGIS at office for some visualization work, but I feel it kinda dump to performing the same tasks several times for visualizing some data on different maps. I am think of automating it ...
4
votes
0answers
141 views
What open source solution would work best for auto extracting features from satellite images? [duplicate]
Possible Duplicate:
Feature Extraction - Land cover
I have been looking for an open source solution which would allow me to define a region (or collection of images) and extract features ...
10
votes
4answers
676 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 ...
15
votes
5answers
607 views
Speed of various raster data formats
I'm having trouble locating any discussion or comparative benchmarking of different raster file formats (e.g., for use in data analysis in R). Does anybody have any insight into why particular formats ...
7
votes
3answers
713 views
How to cluster points based on a kernel density?
I have a large dataset with 36k points representing commercial land uses, each with a field containing the square footage. I have run a kernel density analysis on this dataset, producing a raster ...
16
votes
6answers
510 views
What are sources for current geo-statistical analysis classes/events: open or proprietary
I am keenly interested in geo statistics (and many other words with 3 t's :).
I am not very programatically inclined but have been following several lists with this theme.
One being the R filter on ...
2
votes
1answer
790 views
How to read multiple .gpx files in R [closed]
Suppose I have a number of .gpx files (these contain GPX waypoint data from a Garmin eTrex). I want to load them into R with different names and manipulate them.
I can read one file thus:
...
7
votes
3answers
448 views
How can I make a county-level shape file from a set of points at 30 x30 km spacing?
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 ...
10
votes
4answers
460 views
Does Google Maps API provide statistical tools or even raster to vector conversion?
I am working with a web developer who is working with Google maps API, trying to determine what pre-processing steps I should perform (e.g. in R and GRASS), and what can be done within the google maps ...
8
votes
1answer
484 views
Kriging on GRASS+R
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). ...
3
votes
1answer
344 views
spgrass6 and GIS_LOCK
I would like to thank's everyone first, i learn a lot here (gis.stackexchange) about GIS. I have one question about the use of GRASS within R session, i'm able to do some basic task, but i have one ...
4
votes
2answers
455 views
Altitude Above channel in GRASS 6.4
i'm fairly new to the GIS world and GRASS (come from econometric background), i would like to do some species distribution modeling using R and GRASS.
So i started to read the book of Tomislav Hengl ...
3
votes
1answer
2k views
Convert a shapefile with northing/easting to ASCII raster with latitude/longitude
Linked below is a polygon shapefile whose projection is NAD83 and whose values are LU/LC codes. Coordinates are meters of northing and easting. I would like to convert it to an ASCII raster with ...
6
votes
3answers
1k views
R: Download a large DEM, change projection, and adjust to smaller scale
This is a process that takes just a few seconds in GIS software. My attempt to do it in R uses a large amount of memory then fails. Is there something wrong in my code, or is this just something R ...
4
votes
2answers
971 views
R: overlay a line on a raster stack/brick, and get profile of cell values along the line
I've combed through R's raster functions and vignettes and can't seem to get this working.
I want to specify a line/vector across a raster stack (a DEM and possibly related variables), and get a ...
5
votes
1answer
5k 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
1answer
357 views
Spatial operators in R?
How can I do spatial selections or filters in R? I can do this in PostGIS using (e.g.):
SELECT * FROM mypoint, mypoly
WHERE ST_Within(mypoint.geom, mypoly.geom);
and it is similarly a piece of cake ...
19
votes
6answers
2k views
How to compare two spatial point patterns?
If I have two point pattern distributions within the same geographic region, how would I go about visually and quantitatively comparing those two distributions?
Also assume I have many points within ...
14
votes
3answers
2k views
R to ArcGIS 9.3.1 or 10
I m trying to learn R generally and making statistics for maps. I found some useful tricks for making maps with it but it is not the best you can do. My everyday GIS program is ArcGIS. How I can use ...
33
votes
10answers
3k views
What is the most useful spatial R trick?
R is becoming pretty strong tool for handling and analyzing spatial data. I learned some useful things through questions like these at SO and thought it might be useful to have something simmilar, but ...
10
votes
5answers
602 views
How to implement value-by-alpha map in GIS?
I've been doing some background reading about cartograms recently and stumbled upon interesting alternative - value-by-alpha maps.
Concept is described in more details here and full paper is ...
3
votes
2answers
642 views
Which ESRI defined geographic transformation do I need to use to convert my “ NAD83 Northern Virginia” data into WGS 1984 Web Mercator?
My title pretty much tells it all..
I have a number of datasets in which I want to batch project from NAD83 Northern Virginia Datum into the correct Web Mercator projection..
When I do a straight ...
10
votes
1answer
2k views
Using R with ArcGIS Desktop
In response to comments below, a re-phrasing of the question.
I've used the integration of R with QGIS, and found it a very uesful tool. Having taken a look at the R toolbox extension for 9 and the ...
