Displaying 20 results from an estimated 5000 matches similar to: "Quadrat Variance analysis"
2012 May 31
3
Quadrat counting with spatstat
I have photographs of plots that look like so:
http://r.789695.n4.nabble.com/file/n4631960/Untitled.jpg
I need to divide it up so each circle has an equal area surrounding it. So
into 20 equal segments, each of which contains a circle. Quadratcount is not
sufficient because if I divide it up into 36 equal quadrats, some quadrats
do not contain one of the circles.
I'm not even sure how to
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
2009 Apr 16
3
"reverse truncate" to extract only decimal values
hello there,
Is there a way of truncating in the opposite direction so as to retain only
the values to the right of the decimal??
i.e. rather than:
> trunc(39.5)
[1] 39
i would get something like:
> revtrunc(39.5)
[1] 0.5
I've been searching to no avail but I imagine there is a very simple
solution!
Tyler
--
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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 Jul 13
1
Help get this simple function to work...
I have a function (see below). This function has one object, ID. If I run
the loops by themselves using a character value (ie,"VFFF1-7") instead of
the function object, then the loops work fine. However, when I try to
insert the character value via the function call, it doesn't work. I don't
get an error, but the TotalCover.df dataframe does not update according to
the loop
2005 Dec 05
2
lmer and glmmPQL
I have been looking into both of these approaches to conducting a GLMM,
and want to make sure I understand model specification in each. In
particular - after looking at Bates' Rnews article and searching through
the help archives, I am unclear on the specification of nested factors
in lmer. Do the following statements specify the same mode within each
approach?
m1 = glmmPQL(RICH ~ ZONE,
2009 Jul 13
2
Help me get this function to work...
I have a function (see below). This function has one object, ID. If I run the loops by itself using a character value (ie,"VFFF1-7"), then the loops work fine. However, when I try to insert the character value via the function call, it doesn't work. I don't get an error, but the TotalCover.df dataframe does not update according to the loop criteria. Any obvious problems that
2008 Jun 17
1
Plot point patterns
Hello!
I want to plot a multitype point pattern called "new" in package
spatstat. When I write plot(new) in the graphic window I can see a
strech rectangle with a point inside, not the point pattern.If I
write plot(new$x,new$y) the point pattern is plot ok.The problem
is that I want do the density plots, quadrat count, etc and in
these cases I can?t write density(new$x,new$y), I
2008 May 05
3
merge numerous columns of unequal length
I have numerous objects, each containing continuous data representing the
same variable, movement rate, yet each having a different number of rows.
e.g.
d1<-as.matrix(rnorm(5))
d2<-as.matrix(rnorm(3))
d3<-as.matrix(rnorm(6))
How can I merge these three columns side-by-side in order to create a table
regardless of the difference in length? I wish to analyze the output in a
spreadsheet
2009 Apr 01
2
repeated measures ANOVA - among group differences
I have data on the proportion of clutches experiencing different fates
(e.g., 4 different sources of mortality) for 5 months . I need to test 1)
if the overall proportion of these different fates is different over the
entire study and 2) to see if there are monthly differences within (and
among) fate types. Thus, I am pretty sure this is an RM analysis -( I
measure the same quadrats each month).
2006 May 18
4
Nested design
Dear list members,
I'd like to perform a glm analysis with a hierarchically nested design. In
particular,
I have one fixed factor ("Land Use Classes") with three levels and a random
factor ("quadrat") nested within Land Use Classes with different levels per
classes (class artificial = 1 quadrat; class crops = 67 quadrats; and class
seminatural = 30 quadrats).
I have four
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
2006 Jun 04
1
How to use lmer function and multicomp package?
Dear list members,
First of all thank you for your helpful advices.
After your answeres to my firt mail I studied a lot (R-News n?5) and I
tried to perform my analysis:
First, to fit a GLM with a nested design I decided to use the function
"lmer" in package "lme4"
as suggested by Spencer Graves and Filippo Piro.
I remember to you that my data were:
land use classes, 3 levels
2008 Jun 02
4
NOT-SO-SIMPLE function!
I am trying to set up a function which processes my data according to the
following rules:
1. if (x[i]==0) NA
2. if (x[i]>0) log(x[i]/(number of consecutive zeros immediately preceding
it +1))
The data this will apply to include a variety of whole numbers not limited
to 1 & 0, a number of which may appear consecutively and not separated by
zeros. Below is an example with a detailed
2006 Jun 02
1
geoR, plot of variog4 lines incomplete
I'm using R for Mac OSX version 1.14 (2129) and the geoR package
version 1.6-5 (the current version in the R repository). I'm running
R in OS 10.4.6 on a Mac G4 iBook (933MHz, 640 MB DDR SDRAM). I
searched the R archive and did not find a posting on this issue.
I want to use the variog and variog4 functions of geoR to
characterize the pattern of spatial autocorrelation of tree
2008 Sep 16
1
analyze subsample of dataframe
Hi there,
I'm dealing with a pretty big dataset (~22,000 entries) with numerous
entries for every day over a period of several years. I have a column
"judy" (for Julian Day) with 0 beginning on Jan. 1st of every new year (I
want to compare tendencies between years). However, in order to control for
a leap year (2004), I simply need to subtract 1 from every judy value for
the year
2009 Mar 28
1
Find inflection points using smooth.spline
Is there any way to identify or infer the inflection points in a smooth
spline object? I am doing a comparison of various methods of time-series
analysis (polynomial regression, spline smoothing, recursive partitioning)
and I am specifically interested in obtaining the julian dates associated
with the inflection points inferred by the various models.
Tyler
e.g.
2011 Nov 12
1
Subsetting data leads to funky plots
I'm trying out a basic plot, but something about the way I subset my data
leads to problems with the plot.
Here is the first bit of my data set
year,date,location,quadrat_juvenile,photo_location,photo_exists,genus,count,divers
2005,2005-04-30, 1 Fringing Reef,1, 1 Fringing Reef Coral Transect Pole 1-2
Quadrat 1,t,Acanthastrea,0,HP+MEM
2005,2005-04-30, 1 Fringing Reef,1, 1 Fringing Reef
2006 Sep 12
1
Transformation of a data frame
Dear R-helpers,
Apologies in advance for this (probably) simple question. I've searched the
R Archive and can't seem to find a solution to my problem.
I have a data frame of vegetation quadrat data with the following format:
Q S C
1 A 5
1 B 10
1 C 50
1 D 10
2 A 20
2 E 10
2 C 40
3 D 5
3 F 1
3 G 5
3 B 75
Where Q is the sample (vegetation quadrats), S is the species and C is the