Displaying 20 results from an estimated 5000 matches similar to: "spatial statistics on images, any packages?"
2005 Jul 12
2
Complex plotting in R
Hi list,
I'm looking for a function or a combination of functions to do panel plotting of mixed graph types with the same x axis.
I would like to construct a panel with 3 stacked windows with on top a histogram, below that 2 cdf plots. They all have the same x axis value but different y axis values. Is it possible to construct something like that?
I've looked into the lattice package
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
2013 Apr 16
1
Spatial Ananlysis: zero.policy=TRUE doesn't work for no neighbour regions??
Hello,
I'm new to R and to Spatial Analysis and got a problem trying to create a
Spatial Weights Matrix.
*I us the following code to create the Neighbourslist:*
>library(maptools)
>library(spdep)
>library(rgdal)
>location_County<- readShapePoly("....")
>proj4string(location_County)<- CRS("+proj=longlat ellps=WGS84")
>location_nbq<-
2003 Jun 30
2
spatial correlation test
hello,
I want to do a test for spatial correlation.
I tried it with geary.test() but I don't understand the required input.
x= a numeric vector the same length as the neighbours list in listw (my
sampled data, I assume)
listw= a listw object created for example by nb2listw (well when I check
nb2listw() I get to "neighbours - an object of class nb" - but I couldn't
figure
2004 Mar 19
2
Beginners question
Dear list,
I've been messing around with coding functions in R and it just won't make
sense to me.
Running my analysis by hand on command line is fine and works but because
of the repetitive nature of the job I would like to code a function for it.
My problem:
I would like to read in data from a file in my current working dir.
so my code would look like:
myanalysis <-
2009 Mar 23
1
Iterative Proportional Fitting, use
Hi list,
I would like to normalize a matrix (two actually for comparison) using
iterative proportional fitting.
Using ipf() would be the easiest way to do this, however I can't get my
head around the use of the function. More specifically, the margins
settings...
for a matrix:
mat <- matrix(c(65,4,22,24,6,81,5,8,0,11,85,19,4,7,3,90),4,4)
using
fit <-
2006 Mar 23
1
Cross correlation in time series
Hi list,
I'm working on time series of (bio)physical data explaining (or not) the
net ecosystem exchange of a system (+_ CO2 in versus CO2 out balance).
I decomposed the time series of the various explaining variable
according to scale (wavelet decomposition). With the coefficients I got
from the wavelet decomposition I applied a (multiple) regression, giving
some expected results. The net
2005 Jan 30
1
New user...tips for spdep?
Hello List,
I'm a very new user to the R system. I'm only beginning to learn the
basics, but so far I've been able to do little more than try a few examples,
and of course begin reading the documentation.
My primary motivation for exploring R is the availability of tools like the
'spdep' package for calculating spatial statistics such as Geary's C and
Moran's
2007 Mar 22
1
non-linear curve fitting
Hi list,
I have a little curve fitting problem.
I would like to fit a sigmoid curve to my data using the following equation:
f(x) = 1/(1 + exp(-(x-c)*b)) (or any other form for that matter)
Where x is the distance/location within the dataframe, c is the shift of the curve across the dataframe and b is the steepness of the curve.
I've been playing with glm() and glm.fit() but without
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
2004 Feb 19
1
How to create a "nb" object?
Hi group,
I'd like to do spatial analysis of my data using the spdep package. It appears that a file of class nb is necessary, but I do not find what that should look like and if there is a function that creates such file for me.
How can I create a nb-object of my data points?
Thanks,
René Eschen.
[[alternative HTML version deleted]]
2005 Aug 03
1
help for cell2nb and queencell in spdep package
Dear Dr. Bivand and R-users,
I have a 5 by 5 grid, say, location[1:5,1:5], and I want to know the
indices of 8 neighbours of each cell. For example, for location[2,2], its
neighbour coordinates are [1,1:3], [2,1], [2,3] and [3,1:3]. Sometimes I
also need to remove edge effects (torus = TRUE).
I have tried "cell2nb" function in your spdep package. Here's my example:
> neigh
2005 Nov 23
1
assign() problem
I've written a piece of code (see below) to do a wavelet image
decomposition, during the evaluation of this code I would like to write
the results of some calculations back to the R root directory. I used
assign() to do so because the names should vary when going thrue a
while() loop. For some unknown reason I get an error that says:
Error in assign(varname[i], imwrImage) :
2012 Jul 24
1
unable to run spatial lag and error models on large data
Hi:
First my apologies for cross-posting. A few days back I posted my queries ar R-sig-geo but did not get any response. Hence this post.
I am working on two parcel-level housing dataset to estimate the impact of various variables on home sale prices.
I created the spatial weight metrics in ArcGIS 10 using sale
year of four nearest houses to assign weights. Next, I ran LM tests and
then ran
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
2003 Jul 31
1
spatial statistics vs. spatial econometrics
Dear R users,
I am putting together reading and resources lists for spatial statistics and spatial econometrics and am looking for some pointers from more experienced practitioners.
In particular, I find two "camps" in spatial modelling, and am wondering which approach is better suitied to which situation.
The first camp is along the lines of Venables and Ripley's Chapter 14
2007 Oct 15
1
Distance matrix in SpDep-package
Hello everybody,
I would like to use the SpDep-package (especially the Local Moran index
analysis and the Getis-Ord statistics) in R for analysing my data. However,
I don't have x-y coordinates, but my data is in a distance matrix format. Is
it possible to use the SpDep package with predefined distances as well
instead of letting the program determining the distance itself by the
function
2004 Jun 22
1
k nearest neighbours
Hi there fellow R-users,
Does anyone know of a function which does exactly what knearneigh{spdep}
(finds the k nearest neighbours) does in the package spdep but for more than
2D data?
Regards
Wayne
KSS Ltd
Seventh Floor St James's Buildings 79 Oxford Street Manchester M1 6SS England
Company Registration Number 2800886
Tel: +44 (0) 161 228 0040 Fax: +44 (0) 161 236 6305
2008 Mar 31
1
GeoDa spdep
My question is in regard to the spdep and GeoDa packages. Do you know how
to extract a neighborhood/adjacency matrix from R? I need a matrix that has
all the neighborhoods on the X and Y axis, and then a r=1 when the
neighborhoods touch, and a r=0 when neighborhoods don't touch. I
think the Moran's I functions use a matrix like this when they estimate
Moran's I. I can estimate
2004 Aug 23
2
Reading GAL file
Greetings:
I am trying to work with spdep (everything is "brand new" downloaded this morning). OS = Windows 2000 (also up to date). The code I am using follows:
#example
gal.county=read.geoda("lnpilnd.GAL", row.names=NULL, skip=0)
summary.nb(gal.county)
Error in summary.nb(gal.county) : Not a neighbours list
#end
The gal file works just fine in GeoDa (also up to date).