Displaying 20 results from an estimated 500 matches similar to: "Spatstat - Kest, envelope problem"
2005 Sep 01
2
SpatStat Kest - Error Message help
Hi I'm working with the function Kest in the package SpatStat (under LINUX
with R 2.1.0). In order to evaluate the statistical significance of my
point pattern I'm doing 999 Montecarlo replications. The script that use
the Kest function runs OK for most of the different point patterns that I
have but for a particular point pattern, which have only 17 points, it
runs until the 34th
2006 Jan 12
1
envelopes of simulations
Hello!
I am writing you because I could not plot the confidence envelopes for
functions Jest, Jcross, Jdot, Jmulti, and L, using the Spatstat package.
I have already understood how to do that for Kest or Jest, that is:
JEnv <- plot(envelope(PPPData, Jest))
Where PPPData is my ppp object.
However, for Jcross I must specify the two marks I want to analyse.
That is, usually I would get the
2003 Oct 20
0
calculating K-function (Kest) in spatstat
Dear R-helpers,
After putting my somewhat sparse (21 points) data into a 'ppp' format, I am
unable to calculate the K function using Kest. I get the error "some 'x' not
counted; maybe 'breaks' do not span range of 'x' ". So I tried to calculate
the K function using the swedishpines dataset. Of course Kest(swedishpines)
works fine but when i break it
2010 Apr 14
1
envelope in spatstat
Hi R users,
This query is regarding the use of the 'envelope' function in Spatstat.
My data can be represented as a point process with CONTINUOUS marks:
points <- ppp(x=x,y=y, marks=m, window= wind)
However the marks are alignments (lines), and so have to be treated
differently to normal scalar marks. Hence to create a mcf object with the
appropriate test function for alignment
2008 Mar 04
1
Ripley's K function within envelope--how to change the maximum distance?
Hi--I'm trying to run a Ripley's K analysis on a point pattern within a window
of 1 square km. The maximum distance I want to use is the diagonal of the
window, around 1400m, run in 50m increments.
The function defaults to a 250m maximum--I thought this was simply the way I had
plotted it, but when I exported the data there was nothing over 250m.
I've looked into seq and ginterval,
2005 Sep 30
2
Creating an array [0 to 101] of a list
Hi
I looked, but I didn't find it:
I need an array [0 to 101] where each element is a list (the result of
Kest in spatstat).
I.e. I want to do:
A[2] <- Kest(pp1)
A[3] <- Kest(pp2)
...
A[101] <- Kest(pp100)
How can I create A ?
Rainer
--
Rainer M. Krug, Dipl. Phys. (Germany), MSc Conservation
Biology (UCT)
Department of Conservation Ecology
University of Stellenbosch
Matieland
2006 Feb 27
2
about"Riply's K function"and "envelope"
hi!
I did Riply's K function and envelope in the package "SPATSTAT". When the
species number is less, it can work well and it is quickly. But when the
species number is more(example:2000), it told me"memory limit". So I change
"memory limit". But the speed is very slow. I took 13 hours to run the
programe.
Perhaps there are other methods that can do it. Or just
2005 Oct 10
3
Vectorizing loop
Hi
I have the following loop and would like to vectorize it. Any ideas if
it is possible?
Thanks,
Rainer
Tha Loop:
for (i in 2:Result$NoSims)
{
ppp <- runifpoint(Result$NoPlants)
K <- Kest(ppp)
Result$LSim[i,] <- sqrt(K$iso / pi) - K$r
CM <- (Result$LSim[i,] * Result$LSim[i,]) / abs(K$r[2] - K$r[1])
Result$SigCM[i] <- sum(CM, na.rm=TRUE)
print(i)
flush.console()
}
2009 Feb 20
0
Random labeling hypothesis in spatstat
Hi,
I am trying to test the random labeling hypothesis with my data. I have a point pattern of bird nests and each nest has a mark that it is either predated or not-predated. I want to test the null hypothesis that the K distribution of predation events is equal to the K distribution of all events (nests). This is the code I am using:
Kdif <- function(X,...,i) {
Kidot <-
2012 Jul 02
1
SPATSTAT: Minimum points for a Ripley K to be sensible?
Hello,
What are the minimum number of points in a point pattern before a
clustering analysis using a Ripley K function loses any meaning?
I haven't been able to find much comment in the literature about this
--- instead case examples typically use 100-200 points as a minimum.
Regards,
Sebastian Pucilowski
2005 Oct 10
5
Show Progress in loop
Hi
I have a loop which is doing time consuming calculations and I would
like to be able to have some feedback on where it is in it's
calculations. I tried to simply show the counter variable in the loop,
but id doesn't work as all display seems to be delayed until the loop is
completed. Is there any way of displaying the progress of a loop?
Rainer
The loop:
for (i in
2013 Mar 11
3
Optimization in R similar to MS Excel Solver
Dear all,
I am trying to find the solution for the optimization problem focused on the
finding minimum cost.
I used the solution proposed by excel solver, but there is a restriction in
the number of variables.
My data consists of 300 rows represent cities and 6 columns represent the
centres. It constitutes a cost matrix, where the cost are distances between
each city and each of six centres.
..+
2007 Nov 19
1
Convert from ppp to spp objects
Hi All!
As a new useR, I am currently working in R 2.5.1 to produce Ripley's L (the linear version of Ripley's K) for a spatial point dataset (originally a ESRI shapefile). I have coerced the data to a ppp object (because I was originally using 'kest' in the spstat package to produced Ripley's K) but I need to convert my spatial data to a spp object to be able to use
2012 Nov 23
1
Spatstat: Mark correlation function
I normally use the following code to create a figure displaying the mark
correlation function for the point pattern process "A":
M<-markcorr(A)
plot(M)
I have now started to use the following code to perform 1000 Monte Carlo
simulations of Complete Spatial Randomness (CSR). It is a Monte Carlo test
based on envelopes of the Mark correlation function obtained from simulated
point
2010 Nov 26
1
Plotting envelopes in spatstat
Hello,
Somehow I cannot control my envelope plots on Spatstat package. I would like
to plot an envelope with no legend and also I would like to label the plot
as such:
>plot(envelope(data, nsim=39, main="My K Plot", legend=FALSE,
xlab="Distance")
But somehow the "main", "legend" and "xlab" calls do not have any effect on
the plot. Can someone
2011 Feb 14
0
Spatstat - envelope, Thomas process and Cramer-von Mises
Hi all,
I am using "spatstat" to investigate the spatial structure of some plant
populations, and I want to detect these patters with IPP and a Thomas
process based on pair-correlation function. I know the function "pcfinhom"
is available to characterize the IPP, but I have no idea about how to use
the pcf with Thomas process? Additionally, generating simulation envelopes
2009 Sep 29
1
How to parsing data like this in R
Hi, R-users,
I met a problem:
Items:[Anna 'moi =) akku loppu joskus 4ltä. Kestää kauan nää..'\tAmer, Tuusula (0:20)\t20\t12\t16\t00\t00\t11]/Anne 'Ei jakoa,uus päivä muistio et 4n niin peruin. Hups'\t (0:16)\t0\t12\t18\t00\t00\t11/Elina 'Konsertissa. En tod. vastaa teille'\tEtu-Töölö, Helsinki (2:40)\t24\t12\t18\t00\t00\t11
I want to parsing the above data into the
2004 May 29
1
Rhelp: Need help interpreting plots in spatstat
Hello everybody--
I have been playing with my data in spatstat, and what I'd like to
present is a basic exploratory spatial analysis. I have used the
following code, using a ppp.object called tsdspoints. The code
develops the simulations and the envelopes I want, but I don't
understand my first plot here, the [tsds.ghat.short$r,
tsds.ghat.short$raw]...I cobbled together this code
2020 Aug 15
2
Bug: Dovecot appending "MISSING_DOMAIN" to fetch envelope responses
Hi all,
I'm seeing Dovecot include the string "MISSING_DOMAIN" in fetch
envelope requests when an mailbox's `addr-spec` part does not have a
`domain` part.
For example:
> C: a022 uid fetch 40 (envelope rfc822.header)
> S: * 5 FETCH (UID 40 ENVELOPE ("Sat, 15 Aug 2020 12:53:05 +1000"
> "test {{name}}" (("Michael Gratton" NIL
2005 Jun 01
0
cor.test on spatial data
I have spatial data on various species of trees within plots. What I'd like to know is if their patterns are positively associated or not. Could I use cor.test on the values generated by Kest or Gest functions? or would it be more powerful to do a G i to j and then G j to i analysis instead?
Thanks,
Suzie
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