Displaying 20 results from an estimated 3000 matches similar to: "New package: simstudy"
2007 Sep 24
0
Need help to create a monotone missing data pattern
Hi
I've simulated multivariate longitudinal. The data is a mixture of conitnous
and categorical data. I've stored it in matrix form with the time dependent
variables as colons. Now I want to create a monote missing data pattern
starting of with MCAR-missingnes and different proportions of
missingdata and then refine the function to handle MAR and NMAR. Is there
anybody that could help or
2011 Jun 03
3
Not missing at random
Hello!
I would like to sample 30 % of cases (with at least 1 value lower than 3) and
among them I want to set all values lower than 3 (within selected cases) as NA
(NMAR- Not missing at random). I managed to sample cases, but I don’t know how
to set values (lower than 3) as NA.
R code:
x <-
2010 Apr 04
2
logistic regression in an incomplete dataset
Dear all,
I want to do a logistic regression.
So far I've only found out how, in a dataset of complete cases.
I'd like to do logistic regression via max likelihood, using all the study
cases (complete and incomplete). Can you help?
I'm using glm() with family=binomial(logit).
If any covariate in a study case is missing then the study case is
dropped, i.e. it is doing a complete case
2011 Feb 07
1
multiple imputation manually
Hi,
I want to impute the missing values in my data set multiple times, and then
combine the results (like multiple imputation, but manually) to get a mean
of the parameter(s) from the multiple imputations. Does anyone know how to
do this?
I have the following script:
y1 <- rnorm(20,0,3)
y2 <- rnorm(20,3,3)
y3 <- rnorm(20,3,3)
y4 <- rnorm(20,6,3)
y <- c(y1,y2,y3,y4)
x1 <-
2015 Oct 22
0
C_LogLin (stats/loglin)
Kai,
Apologies for the double message, it didn't go to the list last time.
On Thu, Oct 22, 2015 at 9:59 AM, Kai Nitschke <
kai.nitschke at uniklinik-freiburg.de> wrote:
>
> ?.Call? calls the C/C++ function ?C_LogLin?. But when I am running it line
> by line I get
> the following error on line 23/24:
> Error: object 'C_LogLin' not found
>
> Hence, my
2015 Oct 22
2
C_LogLin (stats/loglin)
Hi everyone,
I have a question regarding a C function of the "stats" package in R.
I tried to understand the ?loglin? basic function of the ?stats?
package implemented in
R. The implemented function itself runs without any problem (perhaps
see sample). When I
ran it line by line it stopped at the lines 23-24 of the
loglin-function; (the following line):
z <- .Call(C_LogLin,
2005 Nov 14
1
Little's Chi Square test for MCAR?
Hi.
Can anyone point me to any module in R which implements "Little's Chi
Square test" for MCAR.
The problem is that i have around 60 behavioural variables on a 6 point
categorical scale which i need to test for MCAR and MAR. What i can make
out from preliminary analysis is that moderate (0.30 to 0.60)
correlations may be present in several variable pairs leading me to
suspect
2001 Feb 27
1
Patch to coplot.R
---1149173172-1804289383-983267779=:26068
Content-Type: TEXT/plain; charset=us-ascii
Hello,
and a big thank you for providing R!
Please find attached a diff for coplot which you may want to consider
for the next release. The diff is against R 1.2.2. The reasons for this
patch are:
1. The boxes of coplot did not align very well with the panel graphs if
applied to a factor
2. Putting the
2012 Aug 13
1
R-help question
Hi there,
I have subscribed to R-help but am not sure how to view or post questions? I think this is the right way.
I am planning on doing a multivariate regression investigating the relationship between depression (a continuous variable) and social support variables (mostly continuous, some categorical) among older people. I have a number of demographic and health-related variables that I am
2006 Jan 05
3
A comment about R
Quoting from Thomas's message -
> "On the question of which system really is easier to learn I can
> only comment that this isn't the only question where education,
> as a field, would benefit from some good randomized controlled
> trials."
A Randomized Controlled Trial?:
Doing such trials would be a 30-year project. The entry criterion
might be at
2007 Aug 15
3
Covariance of data with missing values.
I have a data matrix X (n x k, say) each row of which constitutes an
observation of
a k-dimensional random variable which I am willing, if not happy, to
assume to be
Gaussian, with mean ``mu'' and covariance matrix ``Sigma''. Distinct
rows of X may
be assumed to correspond to independent realizations of this random
variable.
Most rows of X (all but 240 out of 6000+ rows)
2010 Aug 19
0
Little's MCAR test
L.S.,
Does anyone know if there is an R library which implements Little's MCAR
test for completely at random missing values? It is implemented in SPSS and
SAS, and widely mentioned in the literature.
Thanks in advance!
Sander van Kuijk
--
View this message in context: http://r.789695.n4.nabble.com/Little-s-MCAR-test-tp2331137p2331137.html
Sent from the R help mailing list archive at
2010 Aug 30
1
New to R
I'm relatively new to R, and not particularly adept yet, but I was wondering
if there was a simply way to simulate missing data that are MAR, MNAR and
MCAR. I've got a good work-around for the MCAR data, but it's sort of hard
to work with.
Josh
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2011 Jan 17
1
'Bad authorization' error with Asterisk 1.8
Hello!
I have compiled Asterisk 1.8.1.1 on my SheevaPlug. It works all right for
me, except for one problem that I have encountered: I can only register a
SIP client (X-Lite in my case) if the secret field of the extension is left
blank. Otherwise it throws a 'bad auth' error.
Does anybody have any clue?
--
Arik Goldfeld
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2011 Aug 01
1
Impact of multiple imputation on correlations
Dear all,
I have been attempting to use multiple imputation (MI) to handle missing data in my study. I use the mice package in R for this. The deeper I get into this process, the more I realize I first need to understand some basic concepts which I hope you can help me with.
For example, let us consider two arbitrary variables in my study that have the following missingness pattern:
Variable 1
2010 Oct 12
1
Create DataSet with MCAR type
Dear all
I want to create dataset with MCAR type from my dataset.
I have my dataset with 100 records, and I want to create dataset from this
dataset to missing 5 records.
How I can do it.
THX
Jumlong
--
Jumlong Vongprasert
Institute of Research and Development
Ubon Ratchathani Rajabhat University
Ubon Ratchathani
THAILAND
34000
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2017 Dec 19
1
lm considers removed predictors when finding complete cases
Dear R-devel list,
I realized that removing a predictor in lm through the "-"'s operator in
formula() does not affect the complete cases that are considered. A minimal
example is:
summary(lm(Wind ~ ., data = airquality))
# 42 observations deleted due to missingness
summary(lm(Wind ~ . - Ozone, data = airquality))
# still 42 observations deleted due to missingness, even if only 7
2009 Sep 18
1
some irritation with heteroskedasticity testing
Dear all,
Trying to test for heteroskedasticity I tried several test from the
car package respectively lmtest. Now that they produce rather
different results i am somewhat clueless how to deal with it.
Here is what I did:
1. I plotted fitted.values vs residuals and somewhat intuitively
believe, it isn't really increasing...
2. further I ran the following tests
bptest (studentized
2010 Feb 09
1
"1 observation deleted due to missingness" from summary() on the result of aov()
I have the R code at the end. The last command gives me "1 observation
deleted due to missingness". I don't understand what this error
message. Could somebody help me understand it and how to fix the
problem?
> summary(afit)
Df Sum Sq Mean Sq F value Pr(>F)
A 2 0.328 0.16382 0.1899 0.82727
B 3 2.882 0.96057 1.1136 0.34644
C
2010 Feb 28
1
"Types" of missingness
Dear R-List,
My questions concerns missing values. Specifically, is is possible to
use different "types" of missingness in a dataset and not a
one-size-fits-all NA?
For example, data may be missing because of an outright refusal by a
respondent to answer a question, or because she didn't know an answer,
or because the item simply did not apply. In later analysis it is
sometimes