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Exclude missing values on only 1 variable

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Exclude missing values on only 1 variable

torvon
Hello,

I have many hundred variables in my longitudinal dataset and lots of
missings. In order to plot data I need to remove missings.

If I do
> data <- na.omit(data)
that will reduce my dataset to 2% of its original size ;)

So I only need to listwise delete missings on 3 variables (the ones I am
plotting).

data$variable1 <-na.omit(data$variable1)
does not work.

Thank you

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Re: Exclude missing values on only 1 variable

David Winsemius

On Jul 5, 2012, at 1:25 PM, Eiko Fried wrote:

> Hello,
>
> I have many hundred variables in my longitudinal dataset and lots of
> missings. In order to plot data I need to remove missings.
>
> If I do
>> data <- na.omit(data)
> that will reduce my dataset to 2% of its original size ;)
>
> So I only need to listwise delete missings on 3 variables (the ones  
> I am
> plotting).
>
> data$variable1 <-na.omit(data$variable1)

?complete.cases  # returns a logical vector

data[ complete.cases( data[ , c("var1", "var2", "var3"]) , ]


David Winsemius, MD
West Hartford, CT

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Re: Exclude missing values on only 1 variable

Bert Gunter
Be careful!! The plots could be potentially misleading. The problem is the
nature of the missingness. The approach you are taking is based on assuming
MCAR missingness (look it up, if necessary). If that is not the case --
e.g. if there is censoring, MAR, or informative missingness -- the plots
may be completely misleading.

Missingness in longitudinal data is a very difficult issue. If this is
something you don't know about already, I strongly suggest that you consult
a statistician who does -- not all of us do (I know almost nothing, for
example).

-- Bert


On Thu, Jul 5, 2012 at 10:34 AM, David Winsemius <[hidden email]>wrote:

>
> On Jul 5, 2012, at 1:25 PM, Eiko Fried wrote:
>
>  Hello,
>>
>> I have many hundred variables in my longitudinal dataset and lots of
>> missings. In order to plot data I need to remove missings.
>>
>> If I do
>>
>>> data <- na.omit(data)
>>>
>> that will reduce my dataset to 2% of its original size ;)
>>
>> So I only need to listwise delete missings on 3 variables (the ones I am
>> plotting).
>>
>> data$variable1 <-na.omit(data$variable1)
>>
>
> ?complete.cases  # returns a logical vector
>
> data[ complete.cases( data[ , c("var1", "var2", "var3"]) , ]
>
>
> David Winsemius, MD
> West Hartford, CT
>
> ______________________________**________________
> [hidden email] mailing list
> https://stat.ethz.ch/mailman/**listinfo/r-help<https://stat.ethz.ch/mailman/listinfo/r-help>
> PLEASE do read the posting guide http://www.R-project.org/**
> posting-guide.html <http://www.R-project.org/posting-guide.html>
> and provide commented, minimal, self-contained, reproducible code.
>



--

Bert Gunter
Genentech Nonclinical Biostatistics

Internal Contact Info:
Phone: 467-7374
Website:
http://pharmadevelopment.roche.com/index/pdb/pdb-functional-groups/pdb-biostatistics/pdb-ncb-home.htm

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Re: Exclude missing values on only 1 variable

arun kirshna
In reply to this post by torvon
HI,
Try this:
set.seed(1)
dat1<-data.frame(var1=c(rep(NA,3),1:3),var2=c(1:4,NA,5),var3=c(1:5,NA),var4=rnorm(6,15),var5=runif(6,0.2),var6=rep(NA,6))
 dat1[rowSums(is.na(dat1[,c("var1","var2","var3")]))==0,]
 var1 var2 var3     var4      var5 var6
4    1    4    4 16.59528 0.5981594   NA

A.K.





----- Original Message -----
From: Eiko Fried <[hidden email]>
To: [hidden email]
Cc:
Sent: Thursday, July 5, 2012 1:25 PM
Subject: [R] Exclude missing values on only 1 variable

Hello,

I have many hundred variables in my longitudinal dataset and lots of
missings. In order to plot data I need to remove missings.

If I do
> data <- na.omit(data)
that will reduce my dataset to 2% of its original size ;)

So I only need to listwise delete missings on 3 variables (the ones I am
plotting).

data$variable1 <-na.omit(data$variable1)
does not work.

Thank you

    [[alternative HTML version deleted]]

______________________________________________
[hidden email] mailing list
https://stat.ethz.ch/mailman/listinfo/r-help
PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
and provide commented, minimal, self-contained, reproducible code.

Hi,Try this:


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Fw: Exclude missing values on only 1 variable

arun kirshna
HI,
Try this:
set.seed(1)
dat1<-data.frame(var1=c(rep(NA,3),1:3),var2=c(1:4,NA,5),var3=c(1:5,NA),var4=rnorm(6,15),var5=runif(6,0.2),var6=rep(NA,6))
 dat1[rowSums(is.na(dat1[,c("var1","var2","var3")]))==0,]
 var1 var2 var3     var4      var5 var6
4    1    4    4 16.59528 0.5981594   NA

A.K.





----- Original Message -----
From: Eiko Fried <[hidden email]>
To: [hidden email]
Cc:
Sent: Thursday, July 5, 2012 1:25 PM
Subject: [R] Exclude missing values on only 1 variable

Hello,

I have many hundred variables in my longitudinal dataset and lots of
missings. In order to plot data I need to remove missings.

If I do
> data <- na.omit(data)
that will reduce my dataset to 2% of its original size ;)

So I only need to listwise delete missings on 3 variables (the ones I am
plotting).

data$variable1 <-na.omit(data$variable1)
does not work.

Thank you

    [[alternative HTML version deleted]]

______________________________________________
[hidden email] mailing list
https://stat.ethz.ch/mailman/listinfo/r-help
PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
and provide commented, minimal, self-contained, reproducible code.

Hi,Try this:

______________________________________________
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PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
and provide commented, minimal, self-contained, reproducible code.
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Re: Exclude missing values on only 1 variable

David Winsemius
In reply to this post by David Winsemius

On Jul 5, 2012, at 1:34 PM, David Winsemius wrote:

>
> On Jul 5, 2012, at 1:25 PM, Eiko Fried wrote:
>
>> Hello,
>>
>> I have many hundred variables in my longitudinal dataset and lots of
>> missings. In order to plot data I need to remove missings.
>>
>> If I do
>>> data <- na.omit(data)
>> that will reduce my dataset to 2% of its original size ;)
>>
>> So I only need to listwise delete missings on 3 variables (the ones  
>> I am
>> plotting).
>>
>> data$variable1 <-na.omit(data$variable1)
>
> ?complete.cases  # returns a logical vector
>
> data[ complete.cases( data[ , c("var1", "var2", "var3"]) , ]
>
> data[ complete.cases( data[ , c("var1", "var2", "var3") ] ) , ]
Er, need to add a right - paren  -----here  -----------^
>
--

David Winsemius, MD
West Hartford, CT

______________________________________________
[hidden email] mailing list
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and provide commented, minimal, self-contained, reproducible code.
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