Displaying 20 results from an estimated 1000 matches similar to: "Dichotomous variables"
2008 Aug 06
1
Correlation dichotomous factor, continous (numerical) and ordered factor
Hello R-User!
I appologise in advance if this should also go into statistics but I am
presently puzzled.
I have a data.frame (about 300 rows and about 80 variables) and my variables
are dichotomous factors, continuous (numerical) and ordered factors.
I would like to calculate the linear correlation between every pair of my
variables, because I would like to perform a logistic regression (glm())
2007 Aug 07
2
GLMM: MEEM error due to dichotomous variables
I am trying to run a GLMM on some binomial data. My fixed factors include 2
dichotomous variables, day, and distance. When I run the model:
modelA<-glmmPQL(Leaving~Trial*Day*Dist,random=~1|Indiv,family="binomial")
I get the error:
iteration 1
Error in MEEM(object, conLin, control$niterEM) :
Singularity in backsolve at level 0, block 1
>From looking at previous help
2006 Jun 28
1
Simulate dichotomous correlation matrix
Newsgroup members,
Does anyone have a clever way to simulate a correlation matrix such that
each column contains dichotomous variables (0,1) and where each column
has different prevalence rates.
For instance, I would like to simulate the following correlation matrix:
> CORMAT[1:4,1:4]
PUREPT PTCUT2 PHQCUT2T ALCCUTT2
PUREPT 1.0000000 0.5141552 0.1913139 0.1917923
PTCUT2
2005 Oct 10
1
SEM with dichotomous indicators
Hello,
I'd like to know if there is a way to fit a Structural equation model with
dichotomous indicators (ex: problem with a phone solved/ or not) having
effects on a ordinal variable.
How I do that using R?
Do you have an example with the code in R that you can send to me?
Thanks a lot!
Renata Estrella
UFRJ, Brasil, Rio de Janeiro
Renata Leite Estrella
Assistente de
2009 Jun 14
1
estimate the reliability of a scale with dichotomous items
hi,
How can I compute a reliability score of a scale consisting only of
dichotomous items?
thanks for any help!
2011 Jun 14
1
predictive logistic model cell-biology, non-dichotomous data
Hi everyone,
I would like to fit a predictive model to my data in order to compare
absorbance readings to a toxin standard. This data was obtained by exposing
red blood cells to different toxin concentrations, which lead to the lysis
of the red blood cells, increasing the absorbance (hemoglobin is freed). The
data has a sigmoid shape (see below), so I thought about fitting a logistic
model to the
2002 May 23
1
Multilevel model with dichotomous dependent variable
Greetings-
I'm working with data that are multilevel in nature and have a dichotomous
outcome variable (presence or absence of an attribute). As far as I can
tell from reading archives of the R and S lists, as well as Pinheiro and
Bates and Venables and Ripley,
- nlme does not have the facility to do what amounts to a mixed-effects
logistic regression.
- The canonical alternative is
2013 Sep 06
1
Fwd: calculating dissimilarity index of islands (vegan and betapart)
Dear List,
This is Elaine, a postgraduate studying in bird distributions in East Asia.
I want to calculate Simpson dissimilarity index,
based on a presence/absence matrix of bird species in islands in East Asia.
(matrix row: 36 islands/matrix column: species ID)
(R package vegan to make NMDS and R package betapart)
In most papers using vegan for NMDS and betapart for dissimilarity
2005 Sep 27
1
Simulate phi-coefficient (correlation between dichotomous vars)
Newsgroup members,
I appreciate the help on this topic.
David Duffy provided a solution (below) that was quite helpful, and came
close to what I needed. It did a great job creating two vectors of
dichotomous variables with a known correlation (what I referred to as a
phi-coefficient).
My situation is a bit more complicated and I'm not sure it is easily
solved. The problem is that I must
2016 Apr 16
2
Problem: No p-value for a point-baserial correlation with R
Dear community
I'm pretty new to R and I'm trying to do a Point-baserial correlation for a nominal dichotomous variable with a interval scaled variable. It works fine, but the output just shows me the correlation and nothing else (p-Value would be important).
I tried it with the following codes:
- biseral.cor()
- cor.biseral()
- I also tried a polyserial() I've found on this
2010 Jan 12
1
Non-metric multidimensional scaling (NMDS) help
Hi,
I am currently working on some data and feel that NMDS would return an
excellent result. With my current data set however I have been experiencing
some problems and cannot carry out metaMDS. I have tried with a few smaller
data sets which I created for practice sake and this has worked fine.
I think it is the set up of my data set that is causing me trouble. I have
18 columns and 18 rows,
2010 Jan 20
1
Problem in NMDS
Hi,
I am stuck in one problem when doing nonmetric multidimensional scaling. I use the function 'metaMDS' in the package 'vegan' to work on the presence/absence community data. The problem is when two samples are identical (dissimilarity = 0), metaMDS cannot work with zero dissimilarity.
I don't want to delete the duplicates as they are true samples from different locations.
2023 Mar 27
1
Displaying Dichotomous Variables as fractions in gtsummary Tables
I think questions about gtsummary are better addressed to that project.
They have a link "Getting Help" on their web page; I'd start there:
https://www.danieldsjoberg.com/gtsummary/SUPPORT.html
Duncan Murdoch
On 27/03/2023 2:19 p.m., Deramus, Thomas Patrick wrote:
> Hi R Experts.
>
> Apologies if this has been shared elsewhere, but I haven't been able to find a
2009 Jan 12
3
polychoric correlation: issue with coefficient sign
Hello,
I am running polychoric correlations on a dataset composed of 12 ordinal and
binary variables (N =384), using the polycor package.
One of the association (between 2 dichotomous variables) is very high using
the 2-step estimate (0.933 when polychoric run only between the two
variables; but 0.801 when polychoric run on the 12 variables). The same
correlation run with ML estimate returns a
2009 Jun 24
2
Boxplots: side-by-side
Dear R-sians..
I am trying to plot boxplots with side-by-side option.. I tried some of the
posted suggestions and could not make it work due to unequal sizes of
categories...
e.g.
weekly measured water depth values are categorized into 5 levels based on
their values
such measurement is again categorized into dichotomous levels - based on the
result of a test
I would like generate boxplot of
2012 Jun 09
1
combining different types of graphics (scatterplots, boxplots) using lattice
Dear R users:
I have a continuous outcome variable and four predictors, two continuous and
two dichotomous. i would like to use the lattice plot to create scatter
plots for the continuous predictors and boxplots for the dichotomous
predictors.
with 4 continuous variables, this is what i have been doing:
trial = rbind (
cbind ( cimt$ant.mean, cimt$age, 1 ),
cbind ( cimt$ant.mean, cimt$sbp, 2 ),
2007 May 08
3
ordered logistic regression with random effects. Howto?
I'd like to estimate an ordinal logistic regression with a random
effect for a grouping variable. I do not find a pre-packaged
algorithm for this. I've found methods glmmML (package: glmmML) and
lmer (package: lme4) both work fine with dichotomous dependent
variables. I'd like a model similar to polr (package: MASS) or lrm
(package: Design) that allows random effects.
I was
2011 Jun 02
1
Paid R Help
Hello R people,
I am looking to pay someone to help write some R code.
Inputs:
Study identifier: ID Number for the study, each ID number is for one study only each block set should only be used for that study. This will require that you store the results from the blocks someplace on the file system.
Trait #1: dichotomous rural / urban
Trait #2: dichotomous sick / healthy
Assignment Ratio:
2008 Jul 27
2
Link functions in SEM
Is it possible to fit a structural equation model with link functions in R? I
am trying to build a logistic-regression-like model in sem, because
incorporating the dichotomous variables linearly seems inappropriate. Mplus
can do something similar by specifying a 'link' parameter, but I would like
to be able to do it in R, ofcourse.
I have explored the 'sem' package from John Fox,
2009 Jan 21
1
vegan metaMDS
Hi,
I'm trying to use metaMDS with a dissimilarity matrix of angles, not
Bray-Curtis, and I wanted to know if there is an in-built function to
produce a plot of stress values against dimensions, that could be used to
determine the 'true' dimension of the solution. The number of objects is
only a lowly 8 so any solution higher than 2-dimensional is not likely to be
interpretable,