Displaying 20 results from an estimated 10000 matches similar to: "Missing data and Imputation"
2003 Apr 01
1
Shafer's MI software for S-plus
Greetings folks,
Shafer's S-plus package "norm" for multiple imputation of
missing values in multivariate normal data has been most
kindly and usefully ported to R by Alvaro A. Novo.
Shafer's website
http://www.stat.psu.edu/~jls/
lists four S-plus packages in all:
NORM - multiple imputation of multivariate continuous data
CAT - multiple imputation of multivariate
2003 Jun 20
4
Spedd: R vs S-plus
Hi Folks,
Sorry to raise what has probably been discussed before,
but I an repeatedly struck by the comparative slowness
of S-plus for Windows compared with R for Linux when doing
much the same thing.
I don't have a direct comparison, because they're not
running on the same machine; but machine W has a faster
CPU and more RAM than machine L, yet S-plus on W seems
to take longer by quite
2004 May 12
4
missing values imputation
What R functionnalities are there to do missing values imputation (substantial proportion of missing data)?
I would prefer to use maximum likelihood methods ; is the EM algorithm implemented? in which package?
Thanks
Anne
----------------------------------------------------
Anne Piotet
Tel: +41 79 359 83 32 (mobile)
Email: anne.piotet@m-td.com
2003 Oct 20
2
win.metafile and Linux
Hi Folks,
I see that people have been discussing the win.metafile device
on the list since before 2000.
Yet I have never seen this on a Linux distribution of R.
Is this because the device works by making calls (GPL calls of
course!) to a proprietary Windows library?
In that case I can understand that it would be far from kosher to
implement it on Linux. But I'd like confirmation.
I must
2006 Sep 25
2
Multiple imputation using mice with "mean"
Hi
I am trying to impute missing values for my data.frame. As I intend to use the
complete data for prediction I am currently measuring the success of an
imputation method by its resulting classification error in my training data.
I have tried several approaches to replace missing values:
- mean/median substitution
- substitution by a value selected from the observed values of a variable
- MLE
2004 Apr 19
3
New unique name
In some languages there is a function
gensym()
which returns a new unique name (in the current environment).
This is quite helpful when one has to do temporary assignments.
I could not find such a function in R.
Is there one?
--
Erich Neuwirth, Computer Supported Didactics Working Group
Visit our SunSITE at http://sunsite.univie.ac.at
Phone: +43-1-4277-38624 Fax: +43-1-4277-9386
2004 Dec 16
1
help with multiple imputation using imp.mix
I am desperately trying to impute missing data using 'imp.mix' but always
run into this yucky error message to which I cannot find the solution. It's
the first time I am using mix and I'm trying really hard to understand, but
there's just this one step I don't get...perhaps someone knows the answer?
Thanks!
Jens
My code runs:
2004 Jul 06
5
Converting S-Plus Libraries to R
Dear all!
I'd like to do multiple imputation of missing values with s-plus libraries
that are provided by Shafer (http://www.stat.psu.edu/~jls/misoftwa.html). I
wonder, whether these libraries are compatible or somehow convertible to R
(because I don't have S-plus), so that I can use this functions using the R
Program.
I would be happy if you could tell me,
-if it is possible to use
2006 Oct 17
2
Calculate NAs from known data: how to?
Hi
In a dataset I have length and age for cod. The age, however, is ony
given for 40-100% of the fish. What I need to do is to fill inn the NAs
in a correct way, so that age has a value for each length. This is to be
done for each sample seperately (there are 324 samples), meaning the NAs
for sampleno 1 shall be calculated from the known values from sampleno 1.
As for example length 55 cm
2002 Jul 02
4
XEmacs vs. GNU Emacs?
As a user of only R, I don't use much of the potential of ESS and Emacs.
Without entering a religious feud, is there any reason I should use XEmacs
rather than my current GNU Emacs?
(I looked on the XEmacs site, but I didn't understand the programming
issues they were talking about (over my head).)
Martin Henry H. Stevens, Assistant Professor
338 Pearson Hall
Botany Department
Miami
2007 Sep 21
1
A reproducibility puzzle with NORM
Hi Folks,
I'm using the 'norm' package (based on Shafer's NORM)
on some data. In outline, (X,Y) are bivariate normal,
var(X)=0.29, var(Y)=24.4, cov(X,Y)=-0.277,
there are some 900 cases, and some 170 values of Y
have been set "missing" (NA).
The puzzle is that, repeating the multiple imputation
starting from the same random seed, I get different
answers from the repeats
2002 Dec 03
2
missing values and svd
Dear All,
Is it possible to manage a svd analysis within a matrix containing NA
values. If not how do I could overcome this problem.
Thanks in advance
Antonio
2005 Jan 06
2
patterns of missing data: determining monotonicity
Here is a problem that perhaps someone out here has an idea about. It
vaguely reminds me of something
I've seen before, but can't place. Can anyone help?
For multiple imputation, there are simpler methods available if the
patterns of missing data are 'monotone' ---
if Vj is missing then all variables Vk, k>j are also missing, vs. more
complex methods required when the
2005 Jul 08
2
missing data imputation
Dear R-help,
I am trying to impute missing data for the first time using R. The norm
package seems to work for me, but the missing values that it returns seem
odd at times -- for example it returns negative values for a variable that
should only be positive. Does this matter in data analysis, and/or is
there a way to limit the imputed values to be within the minimum and
maximum of the actual
2005 Nov 09
2
error in NORM lib
Dear alltogether,
I experience very strange behavior of imputation of NA's with the NORM
library. I use R 2.2.0, win32.
The code is below and the same dataset was also tried with MICE and
aregImpute() from HMISC _without_ any problem.
The problem is as follows:
(1) using the whole dataset results in very strange imputations - values
far beyond the maximum of the respective column, >
2000 Nov 10
1
Executing an R function from Java.
Is anyone aware of a mechanism by which I could
execute an R function from within java (say
a servlet).
thanks
Richard Piper
--
Intensive Care Unit, RNS Hospital, Sydney.
Phone: 612-9926-8656 or 8617
FAX: 612-9439-8418
Page: 612-9962-4936
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2000 Nov 13
1
Python and R
I've been doing some prototype simulations in Python, and my plan at
first was to pass the results off to R, but now I would like to make
more of an integrated use of the R routines. I'm curious about the
use of libR.so, but I'm uncertain, still after having looked through
the documentation 'Embedding R in Other Applications' and 'Writing R
extensions' how I can
2000 Oct 17
3
"wizard" for building R-packages...
Suppose one wanted to build an R wizard for packaging...
One would need to specify and create:
package-name/
package-name/Description
package-name/INDEX
package-name/R/
package-name/man/
package-name/src/
>From this, we'd "probably" like to:
- script-up the Description
- provide a script for regenerating INDEX by calling out to the
2000 Nov 01
1
Re: desiderata for data manipulation
> From: rossini@blindglobe.net (A.J. Rossini)
> Date: 01 Nov 2000 07:47:21 -0800
[...]
> Thanks for the pointer to stack/unstack -- now, having been reminded,
> I think I'd seen these float through on the list (still doesn't solve
> the missing modeling routines (parametric GLMMs, some of the
> econometrics stuff -- does R _easily_ do 3SLS?), but they'll appear
>
2002 Jan 22
3
Help with Beta Distribution
First let me confess that I am a R-novice.
I am trying to fit a beta distribution for a dataset using fitdistr(MASS). I
am having difficulties with it because the function tends to fit a
distribution with a range of 0 to 1 (I guess). However, my dataset is not!
Anytips or tricks will be very much appreciated.
Many Thanks.
T. S. Ramanarayanan, Ph.D.
Aventis CropScience
Research Triangle Park,