Displaying 20 results from an estimated 2000 matches similar to: "Multiple imputation on subgroups"
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 <-
2002 Oct 28
2
subsetting character vector into groups of numerics
I'm sure there's a simple way to do this, but I can only think of
complicated ones.
I have a number of character vectors that look something like this:
"12 78 23 9 76 43 2 15 41 81 92 5(92 12) (81 78 5 76 9 41) (23 2 15 43)"
I wish to get it into a list of numerical vectors like this:
$Group
[1] 12 78 23 9 76 43 2 15 41 81 92 5
$Subgroup1
[1] 92 12
$Subgroup2
[1] 81 78 5
2011 Jul 20
1
Calculating mean from wit mice (multiple imputation)
Hi all,
How can I calculate the mean from several imputed data sets with the package
mice?
I know you can estimate regression parameters with, for example, lm and
subsequently pool those parameters to get a point estimate using functions
included in mice. But if I want to calculate the mean value of a variable
over my multiple imputed data sets with
fit <- with(data=imp, expr=mean(y)) and
2009 Mar 10
2
perform subgroup meta-analysis and create forest plot displaying subgroups
Hello,
I'm using the rmeta package to perform a meta analysis using summary statistics rather than raw data, and would like to analyze the effects in three different subgroups of my data. Furthermore, I'd like to plot this on one forest plot, with corresponding summary weighted averages of the effects displayed beneath each subgroup.
I am able to generate the subgroup analyses by simply
2011 Jul 27
1
how to replace values in x by means in subgroups created in ... (not loops)
# Dear all,
# how to replace values in x by means in subgroups created in ...
# replace only these values where y=0 in continous sequence
# replace by mean calculated locally for each subgroup created by
# continous sequence of 0,0,0 in parallel y vector, i.e.
# where there is continous sequence of 0 in data frame vector y
# but we do not replace values in x[i], if y[i]!=0
# we do not want
2008 Oct 14
1
library MICE warning message
Hello.
I have run the command
imp<-mice(mydata, im=c("","pmm","logreg","logreg"),m=5)
for a variable with no missing data, a numeric one and two variables with binary data.
I got the following message:
There were 37 warnings (use warnings() to see them)
> warnings()
Warning messages:
1: In any(predictorMatrix[j, ]) ... : coercing argument of
2012 Jul 13
2
Creating Subgroups in Puppet Dashboard
Hi All,
Is there a feasibility for creating subgroups on the Puppet Dashboard?
Basically the requirement is that we have a huge number of VMs running
designated services. Some of VMs having the same service may yet have
different properties configured on them. We are exploring the feasibility
of having these properties managed through puppet. Currently all these VMs
are put into a single
2009 Nov 29
3
How to z-standardize for subgroups?
Hi folks,
I have a dataframe df.vars with the follwing structure:
var1 var2 var3 group
Group is a factor.
Now I want to standardize the vars 1-3 (actually - there are many
more) by class, so I define
z.mean.sd <- function(data){
return.values <- (data - mean(data)) / (sd(data))
return(return.values)
}
now I can call for each var
z.var1 <- by(df.vars$var1, group,
2011 Jun 15
2
Correlations by subgroups
I'm hoping there is a simple answer to this - it seems that there should be,
but I can't figure it out.
I have a matrix/data frame with three variables of interest - V1, V2, V3.
One, V1, is a factor with x levels (x may be a large number); I want to
calculate the correlation between the other two (i.e. cor(V2,V3)) for each
level, and store it as a vector of length x.
I should think this
2008 Nov 26
1
multiple imputation with fit.mult.impute in Hmisc - how to replace NA with imputed value?
I am doing multiple imputation with Hmisc, and
can't figure out how to replace the NA values with
the imputed values.
Here's a general ourline of the process:
> set.seed(23)
> library("mice")
> library("Hmisc")
> library("Design")
> d <- read.table("DailyDataRaw_01.txt",header=T)
> length(d);length(d[,1])
[1] 43
[1] 2666
2008 Jun 30
3
Is there a good package for multiple imputation of missing values in R?
I'm looking for a package that has a start-of-the-art method of
imputation of missing values in a data frame with both continuous and
factor columns.
I've found transcan() in 'Hmisc', which appears to be possibly suited
to my needs, but I haven't been able to figure out how to get a new
data frame with the imputed values replaced (I don't have Herrell's book).
Any
2005 May 04
3
Imputation
I have timeseries data for some factors, and some missing values are there in those factors, I want impute those missing values without disturbing the distribution of that factor, and maintaining the correlation with other factors. Pl. suggest me some imputation methods.
I tried some functions in R like aregImpute, transcan. After the imputation I am unable to retrive the data with imputed
2010 Aug 10
1
Multiple imputation, especially in rms/Hmisc packages
Hello, I have a general question about combining imputations as well as a
question specific to the rms and Hmisc packages.
The situation is multiple regression on a data set where multiple
imputation has been used to give M imputed data sets. I know how to get
the combined estimate of the covariance matrix of the estimated
coefficients (average the M covariance matrices from the individual
2007 Sep 26
1
using transcan for imputation, categorical variable
Dear all,
I am using transcan to impute missing values (single imputation). I have
several dichotomous variables in my dataset, but when I try to impute
the missings sometimes values are imputed that were originally not in
the dataset. So, a variable with 2 values (severe weight loss or
no/limited weight loss) for example coded 0 and 1, shows 3 different
values after imputation (0, 1 and 2).
I
2018 May 23
0
MICE passive imputation formula
Hi all,
I have a question about multiple imputation within the MICE package. I want to use passive imputation for my variable called X, because it is calculated out of multiple variables, namely Y, Z. Let's give an example with BMI. I know, that if I want to use passive imputation for BMI, I can use the following command:
meth["BMI"] <- "~I(weight/(height/100)^2)"
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
2012 Mar 29
3
How to get the most frequent value of the subgroup
Dear Members of the R-Help,
While using a R function - 'aggregate' that you developed, I become to have a question.
In that function,
> aggregate(x, by, FUN, ..., simplify = TRUE)
I was wondering about what type of FUN I should write if I want to get "the most frequent value of the subgroup" as a summary statistics of the subgroups.
I will appreciate if I can get
2013 Feb 14
2
Plotting survival curves after multiple imputation
I am working with some survival data with missing values.
I am using the mice package to do multiple imputation.
I have found code in this thread which handles pooling of the MI results:
https://stat.ethz.ch/pipermail/r-help/2007-May/132180.html
Now I would like to plot a survival curve using the pooled results.
Here is a reproducible example:
require(survival)
require(mice)
set.seed(2)
dt
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 Mar 15
2
imputation of sub-threshold values
Is there a good way in R to impute values which exist,
but are less than the detection level for an assay?
Thanks,
Jonathan Williams
OPTIMA
Radcliffe Infirmary
Woodstock Road
OXFORD OX2 6HE
Tel +1865 (2)24356