Displaying 20 results from an estimated 1000 matches similar to: "Quadrat counting with spatstat"
2009 Dec 08
1
Quadratcount problem in spatstat
Hi,
I know there are older threads discussing the quadratcount function in
spatstat. Unfortunately, I could not find a solution to my problem there.
I'm analyzing a point pattern in an irregular polygonal window. Both the
window (an entire country) and the points are projected using WGS84.
When I do quadratcount with only one quadrat for the entire country it
holds all my 154 points:
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
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
2017 Nov 28
0
Extract all point in a quadrats by spatstat package
Hi,
With the following code i can divides window into quadrats and counts the numbers of points in each quadrat.
library(spatstat)
X <- runifpoint(50)
quadratcount(X)
quadratcount(X, 4, 5)
quadratcount(X, xbreaks=c(0, 0.3, 1), ybreaks=c(0, 0.4, 0.8, 1))
qX <-? quadratcount(X, 4, 5)
plot(X)
plot(qX, add=TRUE)
But I want to mark each? quadrats? and select/ extract only those points by
2012 Jun 12
1
handle large matrix in R
Dear all,
I've run into a question of handling large matrices in R. I'd like to
define a 70000*70000 matrix in R on Platform:
x86_64-apple-darwin9.8.0/x86_64 (64-bit), but it seems to run out of memory
to handle this. Is it due to R memory limiting size or RAM of my laptop? If
I use a cluster with larger RAM, will that be able to handle this large
matrix in R? Thanks much!
Best,
Hui
2012 Jun 01
1
scaling of parameter errors in a weighted regression using nls
I noticed that nls treats weights as relative and that the absolute size of the weights w in
the following script has therefore no influence on the errors of the parameters reported in the summary
a<-1
b<-3
x<--100:100
y<-a*x+b
yeps<-y+rnorm(length(x),sd=1)
w<-rep(1,length(x))
plot(x,yeps)
lines(x,y)
fit<-nls(yeps~p1*x+p2,start=list(p1=a*1.5,p2=b*1.5),weights=w)
2012 Jun 12
4
How to subset a matrix?
Hi all,
Lets say I have a matrix A which is m x n.
I also have a mask matrix MASK which is m x n with values in T/F, where T
values make a sub-matrix in regutangular shape...
I applied B=A[MASK] and it didn't work as expected...
Any thoughts?
[[alternative HTML version deleted]]
2012 May 31
1
Repost: Expressions returned by GlobalEnv functions and package functions
Hello,
(Sorry for the repost, i am resending in plain text)
I have a function 'ewrap' (see below for definition).
It takes 3 expressions and returns another expression e.g.
map <- ewrap({
len <- length(r$addon)
rhcollect(len,1)
})
becomes:
expression({
NULL
result <- mapply(function(.index, k, r) {
{
len <- length(r$addon)
2012 Jun 15
3
spelling correction using R
hello
I want a code which can correct the spelling mistakes as well as
grammatical mistakes in the sentences...that is if I am writing following
sentence:
I want too meet my frnd bt due to hectic shcedule I cant
I want output in following way:
I want to met my friend but due to hectic schedule I can't.
Thanks in advance
Shilpa Rai
MSc
IIT Bomaby
--
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2012 Jun 12
3
R-SCRIPT Label Calling Method
Hi,
here i have some code...
a <-1
b <- b+1
c <- b+a/20
if c >5
{ d<- 1 }
else { d<- 0 }
i want to repeat this code from the 2nd line [b <- b+1] without using loop.
Actulay i want to use "*Label *" and call *GoTo* method like in other
coding Languages.
For eg:- like this,
a <-1
*LabelBegin :*
b <-
2012 Jun 28
4
Printing a variable in a loop
Dear R Users:
I'm a STATA user converting to R, and I'd like to be to do the following.
#Assign var_1 and var_2 a value
10->var1
20->var2
#Now I'd like to print the values of var_1 and var_2 by looping through
var_1 and var_2 in such a manner:
while(y<3){
print(var_y)
y+1->y
}
In STATA, the "y" appended to " var_" is called the local variable and
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 04
0
Suppressing (or changing) the colours when using spatstat plot.quadratcounts
Hi,
Using the quadrats and quadratcount functions in spatstat, when I go to
plot either of these, I get the quadrats coloured by their identity,
i.e., using a color ramp applied to the sequence of quadrats. This only
happens when the quadrats are applied to an owin which is polygonal,
i.e., when I have an irregularly shaped study area.
There doesn't seem to be any obvious way to
2012 Jun 26
4
increase the usage of CPU and Memory
Dear All,
I have been searching online for help increasing my R code more efficiently
for almost a whole day, however, there is no solution to my case. So if
anyone could give any clue to solve my problem, I would be very appreciate
for you help. Thanks in advance.
Here is my issue:
My desktop is with i7-950 Quad-core CPU with 24Gb memory, and a NVIDIA GTX
480 graphic card, and I am using a
2012 Apr 16
2
Creating a point pattern with spatstat
I have presence/absence data in the following format:
1 2 3 4 5 6 7 8 9 10 11 12
1 1 1 1 1 1 1 1 1 1 1 1 0
2 1 1 1 1 0 1 1 1 1 1 1 0
3 1 1 1 1 1 1 1 1 1 1 0 1
4 1 1 1 1 1 0 1 1 1 1 0 1
5 1 1 1 1 1 1 1 0 0 1 1 1
6 1 1 1 0 0 1 0 0 1 1 1 1
7 1 1 1 1 0 1 1 0 0 0 1 1
8 1 1 1 1 1 1 1 0 0 0 1 0
9 1 1 1 1 0 0 1 0 0 0 1 1
10 1 1 1 1 1 1 1 0 0 0 0 1
11 1 1 1 1 1 1 1 1 1 0 0 1
12 1 1 1 1 1 0 0 0 1 1 1 1
2010 Oct 16
0
Spatstat Tessellation error
Hello R Users,
I am trying to do a quadrat count defined by covariate properties in
spatstat. I have read my elevation raster into R (from ascii) and converted
to class "im" for use in spatstat.
Now I have point data of class "ppp" which window is the same extent as the
elevation image. I can conveniently plot the image and the points on the
image as follows:
2010 Oct 20
0
Spatstat: tessellation problems.
Hello R Users,
I am trying to do a quadrat count defined by covariate properties in
spatstat. I have read my elevation raster into R (from ascii) and converted
to class "im" for use in spatstat.
Now I have point data of class "ppp" which window is the same extent as the
elevation image. I can conveniently plot the image and the points on the
image as follows:
2012 May 31
1
Using RDF/OWL with R?
Hello,
Is there a convenient way to import RDF/OWL data into R?
I'm interested in importing BioPAX/SBPAX data into R to make them
available for a wider audience. One exciting application would be to
use pathway data to explain differential microarray measurements by
identifying upstream nodes that are likely involved in causing the
differences. This could also be used to validate
2009 Mar 28
1
Quadrat Variance analysis
Is there any package or operation in R designed to conduct or facilitate
Quadrat Variance analysis of spatial data? Any leads would be much
appreciated as I have found very little in my searches thus far.
Tyler
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2010 Oct 15
0
tessellation from biological data in spatstat
Hi,
I'm new to this mailing list so apologies if this is too basic. I have
confocal images 512x512 from which I have extracted x,y positions of the
coordiates of labelled cells exported from ImageJ as a.csv file. I also
have images that define an underlying pattern in the tissue defined as
areas of different pixel values 0 or 255 (also 512x512) I've exported
these images as .txt