Displaying 20 results from an estimated 900 matches similar to: "[off-topic] The better analysis"
2011 Mar 10
2
Reshape, melt and cast query
I have a dataset that is based on crop output for a single crop
*sugarcane*...but
each observation is further subdivided into 3 kinds of sugarcane
i have read the file and have also used melt it to sort it on the
basis of *crop
group* using
melt(sugarcane, m=c("Crop_group")) -> canefile
this is how it has cast the data
variable value
1 Crop_group Sugarcane
2012 Feb 19
1
coxme: model simplification using LR-test?
Hi
I'm encountering some problems with coxme
My data:
I'm looking at the survival of animals in an experiment with 3 treatments,
which came from 4 different populations, two of which were infected with a
parasite and two of which were not. I'm interested if infected animals
differe from uninfected ones across treatments.
Factor 1: treatment (3 levels)
Factor 2: infection state
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
2005 Jan 03
0
LME-glmmPQL formulation
Hi all -
R2.0.1 on OSX;MASS library;nlme library
I am trying to emulate the solution to a problem set that has normally
been run in Genstat, using R. The problem that I am having at the
moment is with the following glmm question (using glmmPQL from the MASS
library):
"We have two different forest habitats (first rotation thicket, and
high forest) which we want to survey for the
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
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
2007 Sep 12
2
Nested anova with unbalanced design and corrected sample size for spatial autocorrelation
Hello all,
This may be a simple question to answer, but I'm a little bit stumped with
respect to the calculation of the F statistics in nested anovas with
unbalanced design in R.
In my case, I have 11 vegetation transects (with 1000 10cmx10cm squares),
where we estimated shrub cover. We have two different treatments: wildfire
(4 transects) and prescribed burning (7 transects) and we want to
2012 Jul 01
0
Cumulative Link Models
Dear R community,
I'm trying to analyze a model with an ordinal response variable.
I wonder if clm()s (Cumulative Link Models) are appropriate in my case.
The study compares parasite infestation of porpoises in 1995 and 2009. The degree of infestation is a rank (mild to severe, as ordered factor). In some parasite species clm gives meaningful results. But in one case I started to wonder. In
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, -,
2010 Jul 27
0
3d topographic map [SEC=UNCLASSIFIED]
Hi Sherri,
There are examples of topographic maps which you have been pointed to, however, I suspect that you want to know where you can obtain topographic data from rather than a canned example.
There are quite a few intricacies to the process so I will go through them for you.
(1)
Topography files can be found in the geomapdata library. You will probably want to use the maps package too (if
2005 May 19
0
Random/systematic selection of rows in a matrix
Hi R people:
I am new to R. I am writing a function to (1) produce a sparse
stochastic Gaussian 2D field and (2) perform a systematic
transect sampling on this field, this carried out many times
in a simulation framework. My function does a good job at
producing the random field (a matrix of zeros and some
manifestations of the stochastic process, depending on a
parameter of the function
2011 May 28
2
Nested design
Dear R-users,
I have the following problem. I have performed an experiment for which I
gathered a lot of data which I now want to test. The problem is that I
cannot find an appropriate test in R (I am a starter) and someone might give
me a hand. This is what I have done:
Across three sites (Site), I have laid out five transects (Trans)...meaning
five transects in each sites. In each transect I
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
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:
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
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
2011 Aug 03
2
cdplot error
Fairly new at this.
Trying to create a conditional density plot.
>cdplot(status~harvd.l,data=phy)
Error in cdplot.formula(status~harvd.l,data=phy):
dependent variable should be a factor
What does this error mean? Status is a binary response of infestation (0/1)
and harvd.l is the log of timber harvest density per catchment.
Thanks.
--
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2018 Feb 22
2
Filtrado de variables
El jue, 22-02-2018 a las 09:52 +0100, Carlos Ortega escribió:
> Aquí tienes un par de formas...
... y aún una más, con el siempre fiel lenguaje SQL:
library(sqldf)# corriendo antes lo que hizo don Carlos pero dejándolo como un data.frame tradicional:DF<-as.data.frame(DF)sqldf("select * from DF where resultado=' NA '")
¡Saludos!
--
«...homines autem hominum causa esse
2005 Jul 13
5
maps drawing
Hello,
is there a package in R that would allow map drawing:
coastlines, country/state boundaries, maybe
topography,
rivers etc?
Thanks for any guidance,
Mark