Displaying 20 results from an estimated 1000 matches similar to: "logistic regression and 3PL model"
2005 Feb 20
1
logistic regression and 3PL model
Hello colleagues,
This is a follow up to a question I posed in November regarding an analysis
I was working on. Thank you to Dr. Brian Ripley and Dr. John Fox for
helping me out during that time.
I am conducting logistic regression on data set on psi (ESP) ganzfeld
trials. The response variable is binary (correct/incorrect), with a 25%
guessing base rate. Dr. Ripley suggested that I
2005 May 07
1
Incorrect libxml2.2.dylib version on Tiger install
Hi all,
I have just installed OSX Server 10.4 and R comes up with the
incompatible libxml library message reported by Dan Kelley a few
messages ago. Xcode 2 does not ship with Tiger Server. I installed
the X-Windows code. I can report that the version of libxml2.2 that is
installed in this case is the version 8.0.0 dylib.
[6]sboker at munimula:/usr/lib % ls -l libxml2.2*
-rwxr-xr-x 1
2003 May 13
0
bug in promax?
I was wondering whether the following inconsistency of the promax
rotation function with the results of a promax rotation using SAS
should be considered a bug in the promax function of R. Any comments
will be highly appreciated.
The following is a loading matrix obtained from a varimax rotation in SAS:
# Factor loadings after varimax rotation
x <- t(array(c(0.78107, 0.35573,
2003 May 01
0
factanal
# I have a question about how factanal is calculating the regression factor
# scores based on an oblique rotation (promax) of the factors.
#
# As is explained in the help file, regression factor scores are
# obtained as
#
# hat f = Lambda' Sigma^-1 x
#
# However, according to Harman's "Modern Factor Analysis" (e.g. second
# edition, pp. 351-352) the formula is
#
# hat f = Phi
2010 Mar 03
1
help R IRT simulation
hello R,
This is about simulation in psychomtrics in IRT in R. I want to simulate b
parameters(item difficulty) with moments of fixed values of mean, st.d,
skewness and kurtosis. Is there any specific IRT package in R with those
functions to control those moments? I have seen other programs that can
control mean and st.d but not skewness and kurtosis.
Thank you,
helen L
[[alternative HTML
2004 Sep 22
5
Issue with predict() for glm models
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2001 Oct 30
2
extracting object names as strings
Hi,
I'm looking for a function which returns the name of the argument
object as a string:
>vect <- 1:3
>function(vect)
"vect"
I've looked at 'name', 'names', 'objects', none seem to do exactly what I
want. ls/objects comes close, but I can't figure out how to force it to
give me only one object name.
daver
2001 Oct 09
3
find indices of nonzero elements
Hi,
Is there a function func(x) where x is an array such that it
returns a list of the indices of all non-zero elements of the array?
for example:
a:
1 0 0
0 0 1
0 1 0
func(a) returns two vectors r and c:
r c
1 1
2 3
3 2
daver
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|David Richmond It works on a |
+ Dept. of Sociology complex scientific
2001 Nov 29
3
pause/get input
Hi,
Is there a simple command to pause a script until the user hits
return? Alternatively, is there a command which prompts the user for some
input and assigns the input into a variable?
dave
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|David Richmond It works on a |
+ Dept. of Sociology complex scientific +
|Saint Mary's College
2010 Nov 03
3
optim works on command-line but not inside a function
Dear all,
I am trying to optimize a logistic function using optim, inside the
following functions:
#Estimating a and b from thetas and outcomes by ML
IRT.estimate.abFromThetaX <- function(t, X, inits, lw=c(-Inf,-Inf),
up=rep(Inf,2)){
optRes <- optim(inits, method="L-BFGS-B", fn=IRT.llZetaLambdaCorrNan,
gr=IRT.gradZL,
lower=lw, upper=up, t=t, X=X)
2010 Feb 19
3
CentOS and Bash History
Hi,
I was wondering if bash or inputrc has changed form CentOS v4 to CentOS v5?
Reason I ask is at the bash cli I can type, for example 'su' and then with
the up and down arrows I can scroll through my history and will only see the
commands that begin with 'su'. In CentOS 5 this isn't the case.
I have added some code to my inputrc file to make this work in CentOS 4 as
2005 Feb 02
1
Hangup detection with TDM400 in UK
When a caller hangs up (e.g. after leaving a voicemail), my British Telecom
exchange sends a continuous tone for about 15s and then silence. I can't get
asterisk to recognise this tone as a hangup indication.
I have tried indications.conf with both country=uk and country=us.
My zapata.conf has busydetect=yes, callprogress=yes and I've tried setting
busycount from 1 through 7
I am using
2010 Mar 10
2
help R non-parametric IRT simulation
Hello R,
I am looking for non-parametric simulation in IRT. Is there any IRT
package that does non-parametric simulation?
helen L
[[alternative HTML version deleted]]
2003 Sep 18
1
2.2.8a newbie path problem
Hi
I'm presently installing 2.2.8a on Mandrake 9.1
I'm a newbie to Linux as well as Samba, so it's been fun...
When I first installed Linux I installed Samba from the discs (2.2.7a), but
on reading up on the subject it became clear that I should give installing
the source a go.
My problem is this - I don't think I have rerouted all of the paths to
usr/local/samba from what
2001 Sep 14
3
stuff I used to do in Matlab
Hi,
I'm new to R, and trying to map stuff I knew how to do in Matlab
to R. For instances, in matlab, sum(x) gave the column sums of
matrix(/vector) x. In R it just gives the sum of all the elements,
regardless of their form (vector or matrix). Is there a simple way to
return a vector of column sums for a matrix? Also, in Matlab binary
operators exist for concatenating a matrix onto the end or
2002 Mar 20
7
how does while work
i am having some problems with a program that i am writing and i think that
knowing how the while command works will help me to figure out where i am
going wrong
*when do you get kicked out of a while loop?*
(i.e., in the following example what would the final value of 'a' be?) i
thought it would be 99 but running it in R i get 101 (and 101 for x too!)
while (x <100) {
for (i in
2018 May 15
2
questions on subscores.
Hello,
I want to compute Wainer et al's augmented subscore(2001) using IRT but I can't find any packages or relevant code.
There is a 'subscore' package in R, but I think it only gives functions to calculate augmented subscores using CTT(classical test theory).
Is there other package or code to compute subscores using IRT? If it is not, is there any plan to develop it in
2008 Feb 28
0
problem with the ltm package - 3PL model
Hi Xavier,
the reason you observe this feature is that in the 'constraint'
argument you should specify the values under the additive
parameterization, i.e., when in the second column of the matrix
supplied in 'constraint' you specify 2, then you need to provide the
easiness parameters (not the difficulty parameters) in the third
column. Check the Details section of ?tpm() and
2008 Jul 01
17
Memory leak scripts
Hola, I am trying to isolate the memory leak I suspect in a mailman
installation ? I found:
http://blogs.sun.com/sanjeevb/date/200506
It gives an error:
god at irt-smtp-02:~ 9:21am 65 # ./memleak.d 10312
dtrace: failed to compile script ./memleak.d: line 3: probe description
pid10312:libc.so.1:malloc:entry does not match any probes
I am on SunOS 5.10 Generic_127112-07 i86pc i386 i86pc
Are
2019 Oct 23
2
issues with Asterisk CLI
Hello,
I have Asterisk 16.2 on Debian.
In the Asterisk CLI, I would like to change 2 things:
1) change the keybindings for commandline editing
(what in bash is called "readline" editing of the command line)
The CLI is missing some very useful keybindings, and even worse, has
misconfigured others, For instance, "ctrl"+"w" should delete the last
word backward. But