similar to: Simulate Strauss process in 3D

Displaying 20 results from an estimated 8000 matches similar to: "Simulate Strauss process in 3D"

2009 May 24
1
about strauss process
i have trouble in using spatstat package. i want to simulate a community under the Strauss process,which has a parameter gamma that controls interaction strength between points,and Strauss process is defined only for 0 ¡Ügamma ¡Ü 1 and is a model for inhibition between points. my problem is that in my data, many species's estimated gamma is larger than one.so if i still wanna simulate
2007 Jul 13
1
spatstat - Fitting a Strauss model with trend determined by kernel density smoother
Dear r-help, I would like to use the 'ppm' function of the 'spatstat' package to fit a Strauss inhibition model. I understand that I can specify a parametric model for the "background" trend, but how would I specify a trend which is estimated using a Kernel density smoother? In particular, I would like to use the 'kde' function of the 'ks' package to
2008 Sep 17
1
Source code of Strauss Process
Dear all, I want to simulate a Strauss Hard Core process in 3D. I have found that someone else tried to do the same and he recived this answer, "If you need this immediately, I suggest you follow Brian Ripley's advice. This probably involves downloading a source tar file of the R package and finding the Fortran code in library/spatial/src/. The Fortran should be edited to generate 3D
2006 May 17
4
uniform and clumped point plots
I am trying to generate two dimensional random coordinates. For randomly distributed data I have simply used >xy<-cbind(runif(100),runif(100)) However I also want to generate coordinates that are more uniformly distributed, and coordinates that are more contagiously distributed than the above. Can anyone make any suggestions Thanks. Dr Terry Beutel Rangeland Scientist Animal
2002 May 07
4
attractive spatial point process?
Hi all, before I roll my own, naive implementation of a particular spatial point process, I thought I'd ask whether this has already been done. Specifically, I am looking for essentially the opposite of the Strauss and Mate'rn processes included in library(spatial) and documented in MASS. I am examining daily travel patterns, focusing on just the destinations of trips, not the
2005 Dec 09
1
O-ring statistic
Rainer M Krug writes: > Thorsten Wiegand used in his paper Wiegand T., and K. A. Moloney 2004. > Rings, circles and null-models for point pattern analysis in ecology. > Oikos 104: 209-229 a statistic he called O-Ring statistic which is > similar to Ripley's K, only that it uses rings instead of circles. > > http://www.oesa.ufz.de/towi/towi_programita.html#ring
2006 Oct 23
1
Worm distribution :-)
You are talking about random point patterns, since the glow-worms appear as ``stars'' (= points). See the package ``spatial'' (which comes with R) and try simulating a pattern using Strauss(). Or install the package ``spatstat'' from CRAN --- in this package there is a variety of ways to simulate ``regular'' random point patterns --- rMaternI, rMaternII, rSSI,
2005 Jan 27
7
getting package version inside .First.lib
Greetings - Is it possible, inside .First.lib, to find out the version number of the package that is being loaded? If only one version of the package has been installed, we could scan the DESCRIPTION file, something like .First.lib <- function(lib, pkg) { library.dynam("spatstat", pkg, lib) dfile <- system.file("DESCRIPTION", package="spatstat")
2014 Jul 30
2
listof
Dear R developers A question about the class 'listof', defined in package 'stats'. Other than its definition and use in the code for 'anova', we can't see that the class 'listof' is used for anything else (in recommended packages, or elsewhere). In the spatstat package we have been using a 'listof' to represent a list of spatial objects of the same
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
2008 Apr 26
6
quasi-random sequences
Dear list useRs, I have to generate a random set of coordinates (x,y) in [-1 ; 1]^2 for say, N points. At each of these points is drawn a circle (later on, an ellipse) of random size, as in: > N <- 100 > > positions <- matrix(rnorm(2 * N, mean = 0 , sd= 0.5), nrow=N) > sizes<-rnorm(N, mean = 0 , sd= 1) > plot(positions,type="p",cex=sizes) My problem is to
2013 Mar 21
3
spatstat error
Good day Im working with some coordinates, and want to create a PPP object, I found that error: > Datos=read.table("puntos_texto.txt",dec=".",sep="\t",header=T) > summary(Datos) id y x Min. : 1.0 Min. :1013581 Min. :1177842 1st Qu.: 821.2 1st Qu.:1014442 1st Qu.:1179658 Median
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,
2012 Mar 28
3
Spatstat users.
This is a cry for help. My apologies for taking up bandwidth with an issue that is not really on topic. But I really do want to acquire the requested information. In the course of preparing my PBRF (performance based research funds) portfolio for the upcoming PBRF exercise here in New Zealand, I have been advised that I should provide some estimate of the number of "active users" of
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
2008 Oct 22
1
Spatstat help - quadratcount query
Hi all, I am using quadratcount in spatstat to divide a window containing a point pattern into a grid of quadrats containing the intensity of points in each quadrat. My data is in UTM co-ordinates. My window is defined as follows: >p15<-ppp(x,y,window=owin(c(341710,342100),c(3126465,3126780)),marks=NUL L, checks=TRUE) Giving me a distance of 390m in the 'x' direction and 315m in
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
2007 Apr 27
1
Quadratcount() plotting in R spatstat
Hello, I am trying to plot a quadratcount object over a ppp object in the spatstat package. I ultimately want to get something like this http://bg9.imslab.co.jp/Rhelp/R-2.4.0/src/library/spatstat/man/images/big_quadratcount_001.png http://bg9.imslab.co.jp/Rhelp/R-2.4.0/src/library/spatstat/man/images/big_quadratcount_001.png See
2009 Jan 11
2
I'm looking for a book about spatial point patterns (Diggle, 2003)
To understand some functions about spatial point patterns in "spatstat" ,I should know some background about it, and the best way is to read the monograph, and "Statistical Analysis of Spatial Point Patterns" (2nd edt.) is a better choise. But I can not find it anywhere I can. Who can help me? Thank you! ----- unangu at gmail.com -- View this message in context:
2007 Mar 26
2
sampling from the uniform distribution over a convex hull
Ranjan Maitra writes: > Does anyone have a suggestion (or better still) code for sampling > from the uniform distribution over the convex hull of a set of > points? This is implemented in library 'spatstat'. If x and y are vectors of coordinates of your initial set of points, library(spatstat) W <- convexhull.xy(x, y) P <- runifpoint(42, W) will compute