Displaying 20 results from an estimated 800 matches similar to: "Re: Tetrachoric and polychoric correlations, Polycor package"
2004 Dec 09
0
Re: Polychoric correlations
This is a bit late, but:
> About two years ago there was a thread about this which suggested that at
> that time nobody had these coefficients ready to go.
> (a) has anyone in the meanwhile programmed them?
http://www.qimr.edu.au/davidD/R/polyr.R
> (d) I appreciate this last item is not strictly an R question, but my
> intention is to use these as input into the sem package for
2008 Sep 01
1
Polychoric and tetrachoric correlation
Hi there,
Am I correct to believe that tetrachoric correlation is a special case
of polychoric correlation when there are only two levels to the ordered
factor? Thus it should be okay to use hetcor from the polycor package
to build a matrix of correlations for binary variables?
If this is true, how can one estimate 95% confidence intervals for the
correlations? My guess would be
mat =
2010 Apr 02
2
tetrachoric correlations
Hi,
Is there any R library/package that calculates tetrachoric correlations from given marginals and Pearson correlations among ordinal variables?
Inputs to polychor function in polycor package are either contingency tables or ordinal data themselves. I am looking for something that takes marginal distributions and Pearson correlation as inputs.
For example, Y1=(1,2,3) with P(Y1=1)=0.3,
2004 Nov 28
2
Tetrachoric and polychoric ceofficients (for sem) - any tips?
About two years ago there was a thread about this which suggested that at
that time nobody had these coefficients ready to go.
(a) has anyone in the meanwhile programmed them?
(b) I think I can see how to do the tetrachoric one with mvtnorm on similar
lines to an example on the help page so will try that if nobody else
already has
(c) looking at the polychoric one makes me realise yet again
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
2011 May 11
3
Vermunt's LEM in R
I don't know of any R package that can match all the functionality of LEM
eg fitting equality constraints to model parameters a la LISREL.
WRT dumping tables, I would have thought that as.data.frame.table does
pretty much what you want, [not tested]
newtab <- as.data.frame(table(a,b,c))
cat("dim\n")
for(i in seq(1, ncol(newtab)-1) {
cat(nlevels(newtab[,1]," ")
}
2006 Jun 23
2
Tetrachoric correlation in R vs. stata
I hope someone here knows the answer to this since it will save me from
delving deep into documentation.
Based on 22 pairs of vectors, I have noticed that tetrachoric
correlation coefficients in stata are almost uniformly higher than those
in R, sometimes dramatically so (TCC=.61 in stata, .51 in R; .51 in
stata, .39 in R). Stata's estimate is higher than R's in 20 out of 22
2007 Dec 19
1
Correlation when one variable has zero variance (polychoric?)
Hi,
I'm running this for a simulation study, so many combinations of parameter
produce many predictions that I need to correlate with data.
The problem
----------------
I'm using rating data with 3 to 5 categories (e.g., too low, correct, too
high). The underlying continuous scales should be normal, so I chose the
polychoric correlation. I'm using library(polychor) in its
2005 Apr 18
1
polycoric correlation
Dear R-users
Could anyone tell me which library contains a function
to compute polycoric correlations?
I wonder the same question was asked a while ago, but
I could not locate the mail in the R-help archives.
Sorry for bothering you.
Sincerely
------------------------
Hiroto Miyoshi
????
h_m_ at po.harenet.ne.jp
2006 Dec 01
3
error in hetcor function (polycor package)?
I have been using the hetcor function in the polycor package. When I
don't specify the use option everything runs smoothly. However, when I
specify use either as "pairwise.complete.obs" or "complete.obs" I get
this error
Error in optim(rho, f, control = control, hessian = TRUE, method =
"BFGS") :
non-finite value supplied by optim
Is this an error in
2012 Nov 16
1
polycor package
I am currently working with R's polycor package and I have encountered a
problem. I tried to follow the steps as outlined in the sem.pdf file where
a CFA model is run using polychoric correlations. Every time I run the
command sem(model, data, N=.), I get the following warning message:
Warning message:
In if (orthogonal) { :
the condition has length > 1 and only the first element will be
2000 Jul 17
2
sshd -i problem under 2.1.1p4 as well
I have encountered the same problem with sshd -i (under Mandrake linux 6.1)
as that described by Ben L Perkins, this time with 2.1.1p4: ...
Last login: Mon Jul 17 12:04:50 2000 from orpheus.qimr.edu.au
-bash: ?oe90: command not found
-bash: glorious: command not found
-bash: ?]r90: command not found
-bash: marshall4: command not found
Connection to orpheus.qimr.edu.au closed.
log:
Jul 17
2007 Aug 30
0
R-help Digest, Vol 54, Issue 30
Ron Crump wrote:
> Hi,
>
> I have a dataframe that contains pedigree information;
> that is individual, sire and dam identities as separate
> columns. It also has date of birth.
>
> These identifiers are not numeric, or not sequential.
>
> Obviously, an identifier can appear in one or two columns,
> depending on whether it was a parent or not. These should
> be
2007 Jul 13
2
nearest correlation to polychoric
Dear all,
Has someone implemented in R (or any other language)
Knol DL, ten Berge JMF. Least-squares approximation of an improper correlation matrix by a proper one. Psychometrika, 1989, 54, 53-61.
or any other similar algorithm?
Best regards
Jens Oehlschl?gel
Background:
I want to factanal() matrices of polychoric correlations which have negative eigenvalue. I coded
Highham 2002
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
2010 Jan 03
1
Questions regarding sem using hetcor() function from polycor and diagrams
Hello R Users,
While I have attempted to dig into the R help files and I have not
identified the answer to these questions, I apologize in advance if my
questions were answered in the past. I also recognize that one of my
questions unfortunately verges on statistical rather than code
territory. I have two rather unrelated questions about using the sem and
polycor packages for a relatively
2013 Oct 09
1
Version of L-BFGS-B used in optim etc
Hi.
I just noticed the paper by Morales and Nocedal
Remark on "Algorithm 778: L-BFGS-B: Fortran Subroutines for Large-Scale
Bound Constrained Optimization". TOMS 2011; 38(1): 7
http://www.ece.northwestern.edu/~morales/PSfiles/acm-remark.pdf
which describes a couple of improvements (speed and accuracy) to the
original Netlib code which AFAICT is that still used by optim()
via f2c.
2011 Jun 30
1
Looking for Filliben (correlation test)
Hi R-users,
I need to run Filliben correlation test, but I'm not able to find this
function in any package.
Perhaps it isn't in a package, but sometimes anybody have program this
function or create a routine to estimate it.
I found it in google and I hope what I found it's in this page,
http://genepi.qimr.edu.au/staff/davidD/R/filliben.R
but i can't open it.
Anybody can help me?
2006 Feb 22
1
var-covar matrices comparison
> Date: Mon, 20 Feb 2006 16:43:55 -0600
> From: Aldi Kraja <aldi at wustl.edu>
>
> Hi,
> Using package gclus in R, I have created some graphs that show the
> trends within subgroups of data and correlations among 9 variables (v1-v9).
> Being interested for more details on these data I have produced also the
> var-covar matrices.
> Question: From a pair of two
2006 Aug 04
1
polychoric correlation error
Dear all,
I get a strange error when I find polychoric correlations with the ML method, which I have been able to reproduce using randomly-generated data.
What is wrong?
I realize that the data that I generated randomly is a bit strange, but it is the only way that I duplicate the error message.
> n<-100
> test.x<-rnorm(n, mean=0, sd=1)
> test.c<-test.x + rnorm(n, mean=0,