Displaying 20 results from an estimated 10000 matches similar to: "No subject"
2002 Jul 19
1
No subject
Hi, I am learining how to use R, specifically the princomp() function, and
I am trying to replicate the results I get in SPSS with no luck, can
anyone give me the equivalent options in SPSS' factor analysis routine?
Thanks, Adam
_____________________________________________________________________
Adam F. Simon
Department of Political Science 44 Gowen Hall
University of
2002 Jul 24
2
No subject
Hi, I am trying to use xgobi with R on a windows XP machine. I downloaded the package, which seems to have worked and started on the tutorial supplied. The command
data(laser)
works fine
but the command
xgobi(laser)
returns
C:/PROGRA~1/R/rw1051/library/xgobi/scripts/xgobi.bat -vtitle 'laser' -std mmx C:/DOCUME~1/Adam/LOCALS~1/Temp/xgobi-laser19169
>
with nothing
2014 Aug 06
2
Sieve filter extracting wrong header value on certain mail messages
# 2.2.12: /etc/dovecot/dovecot.conf
# OS: Linux 3.15.4-x86_64-linode45 x86_64 openSUSE 12.3 (x86_64)
Short version:
1) I filter out spam by using a dovecot sieve filter to act based on a
header inserted by bogofilter
2) In some cases, sieve fails to correctly file based on this header
3) Testing with sieve-test indicates that it's testing the wrong header
4) Suggestions? Am I doing
2012 Nov 04
1
structural equations using sem package
Hello
I am using sem to look at the direct effect of one variable on another but i am uncertain if i am progressing correctly.
An example:
covar1<-? matrix(c(0.4,-0.2,3,-0.2 , 0.3,-2 , 3 ,-2 , 60), nrow=3,byrow=T)
rownames(covar1)<-colnames(covar1)<-c("endo","exo","med")
path1<-matrix(c(? ? "exo -> endo",? "g1", NA,
2003 May 24
1
Can Package SEM do mean structural analysis?
Hi.
I am wondering whether Package SEM can do with intercepts and
means in its structural analysis.
If it can not calculate, how can I make a supplemental function
in R?
Many thanks in advance.
--------========----------
Mitsuo Igarashi
mitsu5 at ruby.famille.ne.jp
2002 Aug 13
1
Ex ante forecasting from structural equation models (SEM package)
Dear Helplist,
I want to produce forecasts from a structural equation model. With the SEM
package the model setup and its estimation is possible. However, I have not
figured out how to obtain ex ante forecasts, i.e. applying the Gauss-Seidel
algorithm to the estimated structural equations for provided values of the
exogenous variables (i.e.: y_t = -inv(A)*B*x_t).
Does anyone know if the there is
2001 Apr 28
9
two new packages
I've prepared preliminary versions of two packages that I plan eventually
to contribute to CRAN:
car (for "Companion to Applied Regression") is a package that provides a
variety of functions in support of linear and generalized linear models,
including regression diagnostics (e.g., studentized residuals, hat-values,
Cook's distances, dfbeta, dfbetas, added-variable plots,
2001 Apr 28
9
two new packages
I've prepared preliminary versions of two packages that I plan eventually
to contribute to CRAN:
car (for "Companion to Applied Regression") is a package that provides a
variety of functions in support of linear and generalized linear models,
including regression diagnostics (e.g., studentized residuals, hat-values,
Cook's distances, dfbeta, dfbetas, added-variable plots,
2001 Apr 28
9
two new packages
I've prepared preliminary versions of two packages that I plan eventually
to contribute to CRAN:
car (for "Companion to Applied Regression") is a package that provides a
variety of functions in support of linear and generalized linear models,
including regression diagnostics (e.g., studentized residuals, hat-values,
Cook's distances, dfbeta, dfbetas, added-variable plots,
2010 Oct 25
1
structural equation modeling in sem, error, The model has negative degrees of freedom = -3, and The model is almost surely misspecified...
Hi all,
I am attempting to learn my way through the sem package by constructing
a simple structural model for some of my data on bird diversity,
abundance, and primary productivity.
I have constructed a covariance matrix between these variables as per
the following:
>S_matrix = matrix(c(
>+ 0.003083259, 0, 0,
>+ 0.143870284, 89.7648490, 0,
>+ 0.276950919,
2008 Apr 01
1
SEM with a categorical predictor variable
Hi,
we are trying to do structural equation modelling on R. However, one of our
predictor variables is categorical (smoker/nonsmoker). Now, if we want to
run the sem() command (from the sem library), we need to specify a
covariance matrix (cov). However, Pearson's correlation does not work on the
dichotomous variable, so instead we produced a covariance matrix using the
Spearman's (or
2004 Jan 29
1
Confirmatory Factor Analysis in R? SEM?
Hi
Has anyone used R to conduct confirmatory factor analysis? This email pertains to use of SEM.
For context consider an example: the basic idea is that there are a bunch of observables variables (say study habbits, amount of time reading in the bus, doing homework, helping other do homework, doing follow-up on errors etc.) and one believes that all these variables maybe measured by two or
2003 Apr 02
19
Combining the components of a character vector
Dear Help,
Suppose I have a character vector.
x <- c("Bob", "loves", "Sally")
I want to combine it into a single string: "Bob loves Sally" .
paste(x) yields:
paste(x)
[1] "Bob" "loves" "Sally"
The following function combines the character vector into a string in the
way that I want, but it seems somewhat inelegant.
2010 Nov 10
1
sem: variance explained
Hi, does anyone know if there is a way to extract the variance of each
variable explained in a structural equation model when using the sem()
function?
Thanks,
James Stegen
--
James C. Stegen
NSF Postdoctoral Fellow in Bioinformatics
University of North Carolina
Chapel Hill, NC
919-962-8795
stegen at email.unc.edu
http://www.unc.edu/~stegen/index.html
2002 Jul 22
2
typsize and fscale arguments to nlm
Dear R list members,
I have a question about the proper use of the typsize and fscale arguments
to nlm.
I use nlm in my sem package to fit general structural-equation models,
which entails maximizing a multinormal likelihood with respect to
parameters that represent regression coefficients and covariances of
variables. The magnitudes of these parameters can be very different.
The
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,
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
2013 Jun 23
1
2SLS / TSLS / SEM non-linear
Dear all, I try to conduct a SEM / two stage least squares regression with
the following equations:
First: X ~ IV1 + IV2 * Y
Second: Y ~ a + b X
therein, IV1 and IV2 are the two instruments I would like to use. the
structure I would like to maintain as the model is derived from economic
theory. My problem here is that I have trouble solving the equations to get
the reduced form so I can run
2006 Feb 07
1
elements from 'sem' function
Hi,
I would like to print elements from sem (structural equation modeling)
function (e.g., model-reproduced covariance matrix (C); estimated asymptotic
covariance matrix of parameter estimates (cov)).
How can I do this?
Thanks,
Andr??
--
Andr?? Tavares Corr??a Dias
Laborat??rio de Ecologia Vegetal
Universidade Federal do Rio de Janeiro
CCS-IB-Departamento de Ecologia
Caixa Postal 68020
2004 Jan 02
2
SEM help!!!
I have just started using the SEM package in R, so I'm not sure I'm doing
everything right, but I keep getting an error concerning startvalues and I
can't figure out how to fix it. Is anyone willing to read over my code
and help me out??? Please email me if you are willing to look at my code
and I will send it to you.
Thank you so much, and Happy New Year!
cathy