Displaying 20 results from an estimated 300 matches similar to: "Nested design"
2010 Aug 13
1
loop for inserting rows in a matrix
Dear R friends,
I have a matrix with 2060 rows and 41 columns. One column is Date, another is Transect, and another is Segment. I want to ensure that there are 9 Transects (1 to 9) for each Date, and 8 Segments (1 to 8) for each Transect in the matrix, by inserting rows where these are missing.
I am new to coding, but am trying to write a loop which checks if each of the transects already
2011 Mar 18
1
XYPlot Conditioning Variable in Specific, Non-Alphanumeric Order.
# I need to create an xyplot() where I control the specific order of
# both my conditioning variables. The default code below plots the
# data correctly (dispersed across all 14 columns), but fails in two
# ways. Both the primary conditioning variable (Transect), and the
# secondary conditioning variable (Offset) are in alphanumeric order,
# rather than the specific order I need.
# Here
2010 May 19
3
offset in gam and spatial scale of variables
Hi,
We are analizing the relationship between the abundance of groupers in line
transects and some variables. We are using the quasipoisson distribution. Do
we need to include the length of the transects as an offset if they all have
the same length??
Also, can we include in the gam models variables that are measured at
different spatial scales? We have done an analysis to see what variables
2008 Feb 13
1
lmer: Estimated variance-covariance is singular, false convergence
Dear R Community!
We analyse the impact of climbing activity on cliff vegetation. During
our fieldwork, we recorded 90 Transects in 3 climbing sites. The aim is
to see, if the plant cover (response: Cover) is influenced only by
crevice availability (predictor: Cracs), or, additional, by the distance
to the climbing route (predictor: Distance). Six plots are nested within
one Transect
2011 Mar 18
2
XYPlot Conditioning Variable in Specific, Non-Alphanumeric Order. -- Resending with corrected .txt file
Due to an error on my part, I have renamed the previously attached file from
T_5-04b_LTC-SE-SO-Compared.csv to
T_5-04b_LTC-SE-SO-Compared.txt.
It remains a comma-delimited file so the extension can be changed and used per the script, or loaded separately.
My sincere apologies,
Guy
-----Original Message-----
From: Guy Jett
Sent: Friday, March 18, 2011 1:13 PM
To: 'r-help at
2005 Jan 06
1
GLMM and crossed effects
Hi again. Perhaps a simple question this time....
I am analysing data with a dependent variable of insect counts, a fixed
effect of site and two random effects, day, which is the same set of 10
days for each site, and then transect, which is nested within site (5
each).
I am trying to fit the cross classified model using GLMM in lme4. I
have, for potential use, created a second coding
2002 Sep 11
2
fitting a linear mixed effects model
A non-text attachment was scrubbed...
Name: not available
Type: text/enriched
Size: 1284 bytes
Desc: not available
Url : https://stat.ethz.ch/pipermail/r-help/attachments/20020911/e68e2ecc/attachment.bin
2009 Mar 23
1
Plot Means Line with Standard Deviation as "Whiskers"
Hi list members.
I’ll try to plot the abundance means of nine transects as lines, with five
points on each transect (A to I). I will also need to plot for each point,
it’s standard deviation (once each point will have tree replicates) as
whiskers. Another problem will be that all the points should exist for each
transect, but we know that six of the nine transects will have blanks (A1,
A2, A3, -,
2006 Sep 12
1
Using XY location data to calculate ecological parameters
Dear R gurus,
I have XY data giving the locations of tree seedlings that were
surveyed during a 210 meter belt transect. This belt transect was
taken by stretching a line across the field, then measuring all
seedlings within 1 meter on either side of the line. The end result
was XY coordinates and height for ~1,300 seedlings. I would like to
use that data to calculate density of
2005 Jul 15
1
nlme and spatially correlated errors
Dear R users,
I am using lme and nlme to account for spatially correlated errors as
random effects. My basic question is about being able to correct F, p, R2
and parameters of models that do not take into account the nature of such
errors using gls, glm or nlm and replace them for new F, p, R2 and
parameters using lme and nlme as random effects.
I am studying distribution patterns of 50 tree
2009 Mar 09
1
Zero distance error in corSpatial - correlation structure using lme
Hello,
I am having a problem specifying the correlation structure in lme which
leads to the error: Error in getCovariate.corSpatial(object, data =
data) : Cannot have zero distances in "corSpatial". I have specified a
grouping variable which is the only fix I could find by searching this
error on R-help.
ISee the below example. When my samples (tran) - which are transects
2011 Sep 08
1
random sampling but with caveats!
Hi,
I wonder if someone can help me. I have built a gam model to predict the presence of cold water corals and am now trying to evaluate my model by splitting my dataset into training/test datasets.
In an ideal world I would use the sample() function to randomly select rows of data for me so for example with 936 rows of data in my HH dataset I might say
ss <- sample(nrow(HH), size =
2012 Jul 19
1
expert opinion on lmer
Hello,
I have the following design, counts were collected at different transects,
different depths and different sites at different times. Time is continuous
and assumed to be random, all the others are categorical fixed where
transect is nested within depth which is nested within site.
I would like an expert opinion about the following code where intercept is
modeled as random (I am not sure
2006 Jun 08
2
nested mixed-effect model: variance components
Dear listers,
I am trying to assess variance components for a nested, mixed-effects
model. I think I got an answer that make sense from R, but I have a
warning message and I wanted to check that what I am looking at is
actually what I need:
my data are organized as transects within stations, stations within
habitats, habitats within lagoons.
lagoons: random, habitats: fixed
the question is:
2012 Oct 23
2
plotting multiple variables in 1 bar graph
I'd greatly appreciate your help in making a bar graph with multiple
variables plotted on it. All the help sites I've seen so far only plot 1
variable on the y-axis
Data set:
I have 6 sites, each measured 5 times over the past year. During each
sampling time, I counted the occurrences of different benthic components
(coral, dead coral, sand, etc.) over 5 transects in each site
site
2008 Aug 17
1
before-after control-impact analysis with R
Hello everybody,
In am trying to analyse a BACI experiment and I really want to do it
with R (which I find really exciting). So, before moving on I though it
would be a good idea to repeat some known experiments which are quite
similar to my own. I tried to reproduce 2 published examples but without
much success. The first one in particular is a published dataset
analysed with SAS by
2005 Apr 05
2
Dead wood code
Is there a package, or does anyone have code they are willing to share, that would allow me to simulate sampling of dead wood pieces across an area? I am specifically looking for code to simulate the dead wood distribution as small line segments across an extent, and then I will "sample" the dead wood using different sampling techniques including line transects, fixed area plots, etc.
2009 Aug 13
2
Fitting a quasipoisson distribution to univariate data
Dear all,
I am analyzing counts of seabirds made from line transects at sea.
I have been fitting Poisson and negative binomial distributions to the data
using the goodfit function from the vcd library. I would also like to
evaluate how well a quasi-poisson distribution fits the data. However, none
of the potentially suitable functions I have identified (goodfit(vcd),
fitdistr(MASS),
2011 Feb 09
1
Two Factors and a Numeric Variable in a Plot
Hi list.
I'm trying to plot a graph "by" factors. Exactly, the x axis are my depths
(as.factor), my left y axis are my transects (also as.factor) and I want to
plot the mean and standard deviation (three samples per factor combination)
of my SW (numeric) variable. The second y axis (at the right) will,
probably, need to be displayed several times (for both left y axis
2008 Nov 15
1
GAMs and GAMMS with correlated acoustic data
Greetings
This is a long email.
I'm struggling with a data set comprising 2,278 hydroacoustic estimates of
fish biomass density made along line transects in two lakes (lakes
Michigan and Huron, three years in each lake). The data represent
lakewide surveys in each year and each data point represents the estimate
for a horizontal interval 1 km in length.
I'm interested in comparing