Displaying 20 results from an estimated 200 matches similar to: "Error with sem function df = -6"
2003 Dec 18
1
NUMERIC DERIVATE
UseRs,
I used the optim function
valor.optim <- optim(c(1,1,1),logexp1,method
="BFGS",control=list(fnscale=-1),hessian=T);
and I want to calculate the derivates,
psi1<-valor.optim$par[1]
psi2<-valor.optim$par[2]
psi3<-valor.optim$par[3]
a0=exp(psi1);
a1=exp(psi2)/(20+exp(psi2)+exp(psi3));
a2=exp(psi3)/(20+exp(psi2)+exp(psi3))
2006 Jan 18
1
Breakpoints for multiple variables using Segmented
Hi all,
I am using the package ?Segmented? to estimate logistic regression models
with unknown breakpoints (see Muggeo 2003 Statistics in Medicine
22:3055-3071). In the documentation it suggests that it might be possible to
include several variables with breakpoints in the same model: ?Z = a vector
or a matrix meaning the (continuous) explanatory variable(s) having
segmented relationships with
2007 Jun 27
1
SEM model fit
I wonder if someone could explain why, when I perform confirmatory
factor-analysis model using polychoric correlations why I do not get an
estimated confidence interval for the RMSEA. My experience with these type
models is that I would obtain a confidence interval estimate. I did not get
any warning messages with the output.
RESULTS:
Model Chisquare = 1374 Df = 185 Pr(>Chisq) = 0
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,
2012 Oct 23
1
Minimizing Computational Time
Dear R-users,
May I seek some suggestions from you. I have a long programme written in R
with several 'for' loops inside. I just want to get them out by any elegant
way (if there is!) to reduce the computational time of the main programme.
For instance, is there any smart way for the following programme that will
lessen time?
2012 Aug 30
1
path analysis help
Hi there,
I searched R-help list with "path analysis" as keyword, and learn that
sem package can do it. However, I don't figure out a way to construct
the model for the path diagram as Fig. 1. in Huang et al. (2002)[1].
I try the following code:
huang.cor <- readMoments(diag=FALSE, names=c('x1', 'x2', 'x3', 'y'))
0.76
0.91 0.72
0.94 0.77 0.83
2012 Aug 03
1
SEM standardized path coefficients
Hello,
I have conducted an SEM in which the resultant standardized path coefficients are much higher than would be expected from the raw correlation matrix. To explore further, I stripped the model down to a simple bivariate relationship between two variables (NDVI, and species richness), where it's my understanding that the SEM's standardized path coefficient should equal the correlation
2012 Mar 12
1
SEM eigen value error 0 X 0 matrix
Using R-studio, I am trying to run a structural equation model and I am
running into problems with testing my primary model. Once I specify
everything and try to run it I get this error:
Error in eigen(S, symmetric = TRUE, only.values = TRUE) : 0 x 0 matrix
And when I look at the object for my primary model in my workspace, which is
created after I specify it, it lists all my model components,
2012 Mar 25
3
attempt to access beyond end of device and livelock
Hi Dongyang, Yan,
When testing BTRFS with RAID 0 metadata on linux-3.3, we see discard
ranges exceeding the end of the block device [1], potentially causing
dataloss; when this occurs, filesystem writeback becomes catatonic due
to continual resubmission.
The reproducer is quite simple [2]. Hope this proves useful...
Thanks,
Daniel
--- [1]
attempt to access beyond end of device
ram0: rw=129,
2013 Jan 11
1
problems with package 'segmented'
Dear R-users,
I am trying to understand how the 'segmented'-package works to determine
breakpoints and slopes of regression lines in broken-line regression models.
However, I am not able to repeat the example on the "plant"-dataset,
which was reported in the accompanying paper of the package. (V.M.R
Muggeo, "Segmented: an R package to fit regression models with
2012 Nov 16
1
Interpretation of davies.test() in segmented package
My data:
I have raw data points that form a logit style curve as if they were a time
series. Which is to say they form 3 distinct lines with 3 distinct slopes
in backwards z pattern. A certain class of my data looks essentially flat
to the eye with marginal oscillation. What is important to me is the x
value at which the state change is occurring, in other words, the break
point
Use of
2006 Aug 22
1
Total (un)standardized effects in SEM?
Hi there,
as a student sociology, I'm starting to learn about SEM. The course I
follow is based on LISREL, but I want to use the SEM-package on R
parallel to it.
Using LISREL, I found it to be very usable to be able to see the
total direct and total indirect effects (standardized and
unstandardized) in the output. Can I create these effects using R? I
know how to calculate them
2013 Mar 18
1
"save scores" from sem
I'm not aware of any routine that those the job, although I think that
it could be relatively easily done by multiplication the manifest
variable vector with the estimates for the specific effect.
To make an example:
v1; v2; v3; v4 are manifest variables that loads on one y latent
variablein a data frame called "A"
the code for the model should be like:
model <-specifymodel(
y
2005 Mar 29
3
Query regarding initramfs
Hi
1. Is it possible to load an initrd from initramfs ?
How would you do this if the initramfs is being loaded dynamically in
the kernel
(ie having the initramfs as initrd )
Because in this case, you will say root = /dev/initrd and specify 'initrd'
as your 'initramfs source file'
How will you specify the second initrd source?
Thanks
Rachita.
2006 Jan 14
1
Add cpio implementation to klibc
I was wondering if it would be possible to add a cpio (extraction)
implementation to klibc. Maybe this can be done in a way that the code
could bet shared between klibc and init/initramfs.c in the kernel.
Background of what I'm trying to do: I want to load an initramfs
from flash on a number of different devices. The devices are quite
similar but the partition in flash where the initramfs
2006 Apr 13
1
device-mapper multipath
I am attempting to get multipath working with device-mapper (CentOS
4.2 and 4.3). It works on EVERY install of mine from RH (also v4.2,
4.3), but the same multipath.conf imported to all my installs of
CentOS do not work. Note that I have tested a working 4.2
configuration file from RH on CentOS 4.2 and a working 4.3
configuration (it changed slightly) on CentOS 4.3. Neither worked. Our
production
2003 Mar 11
4
Syslinux: Multi-Disks [feature]
Hi,
I'm the maintainer ROCK Linux (www.rocklinux.org). We are using isolinux
on our Install-CDs for x86 systems.
We - as most other distributions too - are running in the problem that
even minimalistc kernels are slowly growing and sometimes don't fit on
1.44 MB floppies anymore.
2.5.x kernels with initramfs are even bigger than 2.88 MB in some cases...
Until now it always has been
2013 Mar 12
1
Bootstrap BCa confidence limits with your own resamples
I like to bootstrap regression models, saving the entire set of bootstrapped
regression coefficients for later use so that I can get confidence limits
for a whole set of contrasts derived from the coefficients. I'm finding
that ordinary bootstrap percentile confidence limits can provide poor
coverage for odds ratios for binary logistic models with small N. So I'm
exploring BCa confidence
2012 Oct 02
3
Integration in R
Dear R-users,
I am facing problem with integrating in R a likelihood function which is a
function of four parameters. It's giving me the result at the end but
taking more than half an hour to run. I'm wondering is there any other
efficient way deal with. The following is my code. I am ready to provide
any other description of my function if you need to move forward.
2010 Mar 02
2
Using USB Tape drive on Centos 5.3 (kernel 2.6.18-164.10.1.el5PAE)
Hello there
I have been trying to install HP Storageworks DAT72 on CentOS 5 in vain.
On system reboot, neither /dev/st not /dev/sg is available. May you please
lead me through as this is my first time trying to do it
lsmod
Module Size Used by
ipv6 267617 40
xfrm_nalgo 13381 1 ipv6
crypto_api 12609 1 xfrm_nalgo
autofs4