Displaying 20 results from an estimated 10000 matches similar to: "Running mean for spatial data"
2008 Jul 26
2
Spatial Sample
Hi!
How can I make a spatial sample?
Can someone recommend theorical books and materials for this?
--
Raphael Saldanha
UFJF - Brazil
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2004 Aug 25
1
Newbie Question: Spatial Autocorrelation with R Tutorial?
Howdy All,
I am looking for some good tutorials (books, websites, whatever) for calculating/testing for Spatial Autocorrelation using R.
Specifically, I am wanting to test for autocorrelation of a number of variables measured at a set of discrete locations.
Up to this point I have been exploring the "spdep" package and I can get "moran.test" to work, but I am concerned that
2003 Nov 14
1
spatial modeling
I am new to R and have a question about spatial econometrics. I have
noticed that you can easily test for spatial autocorrelation with the
spdep package, but was wondering if any code has been written to correct
for spatial autocorrelation? Or if there is any literature on this?
Thanks. -Jill
***************************************************
Jill L. Caviglia-Harris, Ph.D.
Assistant
2007 Jun 02
2
spatial simulation
Dear R-users,
I'm trying to do some spatial simulation. I have two covariates, Z and C. I want to examine their relationship under different spatial distribution.
I have no problem simulating completely spatial random process but I'm totally stuck on poisson (cluster) pattern. I already have a dataset with Z and C (obs=575) and I know the relationship between them. Using these 575
2006 Mar 21
1
Getting polygons from contiguous grid cells having same value in sp
I have been using the sp package to deal with gridded data. I would
like to know how to extract the vertices (x,y) of polygons that outline
areas of like-valued cells in a grid. Here is a simple 3x3 grid:
2 2 1
1 2 1
1 1 3
x <- c(1,1,1,2,2,2,3,3,3) # define a 3 x 3 array of points
y <- c(1,2,3,1,2,3,1,2,3)
h <- SpatialPoints(cbind(x,y)) # make these an sp object of the points
2007 May 14
1
a question about spatial autocorrelation in R
Dear all,
I am currently facing a problem related to the spatial autocorrelation of
a sample of stations; these stations supply weekly data for a fixed
time-window during the year (namely, 4-6 months per year).
For this reason I'm trying to use the R package 'spdep' (specifically
Moran's I) in order to get rid of it.
Does anyone know how is it possible (if it is...) to
2005 Nov 17
1
Morans I for Spatial Surveillance
Hello,
I am interested in using Morans I for different time intervals to detect disease clusters.
Ultimately I would like to use CUSUM - or similar monitoring statistic to monitor the results of Morans I - similar to the work by
Rogerson (2005) Spatial Surveillance and Cummulative Sum Methods in Spatial and Syndromic Surveillance for Public Health.
Thus far - thanks to the list I have
2005 Jun 09
1
Plot/manage spatial boundary data
I have some disconnected boundary data from a finite element ocean model
and I'd like to make a plot.
Maptools looks promising, but since my data is not in a shapefile or a
map, I'm unclear on what the best way to approach the problem.
>geom[1:10,]
lon lat depth
1 -75.42481 35.58192 16.172
2 -75.40726 35.58567 18.045
3 -75.41351 35.60312 17.333
4 -75.38888 35.58959
2008 May 05
2
Gravity (spatial interaction) models in R
I was wondering if anyone has developed (or is developing) an
implementation for gravity models (spatial interaction) in R. I
conducted several searches on the CRAN website with no luck. Currently
I am estimating parameters via linearization.
Thank you in advance
Melanie Murphy
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2005 Nov 16
1
spatial statistics on images, any packages?
Hi list,
Is there a package that covers the evaluation of spatial statistics on
images and not on point data? I've converted an image matrix to x, y
coordinates and a measurement value but evaluation with the package
spdep (not really designed for image data I suppose) is unworkable. Any
suggestions?
Regards,
Koen
2011 May 04
1
Instrumental variable quantile estimation of spatial autoregressive models
Dear all,
I would like to implement a spatial quantile regression using instrumental variable estimation (according to Su and Yang (2007), Instrumental variable quantile estimation of spatial autoregressive models, SMU economics & statistis working paper series, 2007, 05-2007, p.35 ).
I am applying the hedonic pricing method on land transactions in Luxembourg. My original data set contains
2009 Feb 08
1
Help on computing Geary's C statistic to test for Spatial Autocorrelation
Dear Users:
I have been trying to use the geary.test() function in *R*, but am having
slight difficulty understanding how I am to apply it in my context.
I have 2 matrices:
1) *n x p* matrix of *n* observations with *p* measurements each. It may be
noted that this matrix has a spatial dimension to it, as the
*n*observations are at different geographical locations on a map.
2) *n x n* spatial
2004 Apr 26
2
Spatial Autocorrelation for point data
Hi R helpers,
Is there a function (package?) in R available which tests "spatial
autocorrelation" between points (e.g. vector layer of weather stations)?
(e.g. Moran's I...)
Via the archives we found out that there is a package 'spdep' which uses
grid data for testing spatial autocorrelation.
Thanks a lot,
Jan
2007 Apr 04
5
how to image.plot a XY grid file into a lat-lon map
Hi All,
I have a netcdf gridded file with LCC projection. I can easily use
image.plot to visualize it. However, as the axises are in X,Y, not Lat and
Lon, I could not add state or country maps onto it (or lat lon information).
I do have a grid2d file that describes the lat and lon for each (X,Y) grid,
but the lat and lon are not regularly spaced, so I could not use image.plot.
Does anyone know
2002 Sep 11
1
Question about spatial statistics
I?m tryng to use the SPDEP package in my research in the field of
population genetics. My data set
has the following format:
- x and y : coordinates,
- Z: allelic frequency in each loci (in a total of 8 locis) - this
variable can assume the values 0 ; 0.5 or 1.
The objective is to verify if there is a possible spatial
autocorrelation structure of the allelic frequency in a population of
2002 May 30
1
neighbor.grid and spatial.weights
Anyobody knows if functions neighbor.grid and spatial.weights (from
module spatial) have any 'equivalents' in R ?
Thanks.
JA
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2003 May 21
1
help on spatial data
Hi,
I have a dataset with x and y coordinates and in each point I have an
identity of point, in some cases I can have more then one identity by point.
My dataset is something like this:
> x <- rep(c(1:4),4)
> y <- rep(c(1:4),c(4,4,4,4))
> area1 <- sample(factor(rep(c("a","b","c","d"),4)))
> area2 <-
2007 Mar 12
1
Analysis of 3-dimensional spatial point patterns
I am trying to determine how to evaluate homogeneity of points in
three-dimensional space.
In two-dimensional data, I have used functions available in the Spatial
package
and I've have looked into the spatstat package
but, as far as I can tell, neither appears to handle 3-dimensional
data.
Is there another version, package, or software that does the same type
(G-function,
2002 Mar 20
4
spatial library
Hi everybody,
I want to download the spatial library but I don't find it at the CRAN
list package. Where can I find the package ?
I have to download it to use the function correlogram.
Thanks in advance,
Paola.
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2003 Jun 16
2
Isocontour-lines of spatial data on a rectangular grid (not plots!)
Dear R-Listers,
I have spatial data on an equidistant rectangular grid, similar to
topographic data. I know that there are quite a few R-packages or base
functions that provide nice iso-contours plot, but I don't want a plot, just
the smoothed isocontour line of ONE level (e.g. 10 mm).
Data sets are large, so it would be preferable if the availability of
regular grid data could be exploited,