command to change some vars to missing into my dataset

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command to change some vars to missing into my dataset

Adam Z. Jabir
Hi,

I want to simulate missing at random for my dataset. Do you know an easy way to do it?

I want to try not to have the missing�s for the same observations. I mean if one observation is been selected randomly to have missing I don�t want to have all the var of the same obs missing.

I want to be able to choose rate of missing that should be applied.

Thanks,

Adam


Envoy� � partir de Outlook<http://aka.ms/weboutlook>

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Re: command to change some vars to missing into my dataset

Rui Barradas
Hello,

What type of data do you have? A vector? Or is it a matrix, a
data.frame, a list, etc?

Suppose it is a vector named x. Then you could do something like

rate <- 0.2
is.na(x) <- sample(length(x), rate*length(x))

At an R prompt type

?is.na
?sample

Hope this helps,

Rui Barradas

Às 21:28 de 05-07-2018, Adam Z. Jabir escreveu:

> Hi,
>
> I want to simulate missing at random for my dataset. Do you know an easy way to do it?
>
> I want to try not to have the missing�s for the same observations. I mean if one observation is been selected randomly to have missing I don�t want to have all the var of the same obs missing.
>
> I want to be able to choose rate of missing that should be applied.
>
> Thanks,
>
> Adam
>
>
> Envoy� � partir de Outlook<http://aka.ms/weboutlook>
>
> [[alternative HTML version deleted]]
>
>
>
> ______________________________________________
> [hidden email] mailing list -- To UNSUBSCRIBE and more, see
> 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.
>

______________________________________________
[hidden email] mailing list -- To UNSUBSCRIBE and more, see
https://stat.ethz.ch/mailman/listinfo/r-help
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and provide commented, minimal, self-contained, reproducible code.
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Re: command to change some vars to missing into my dataset

Jim Lemon-4
In reply to this post by Adam Z. Jabir
Hi Adam,
Looks like you have a matrix or data frame and want to change one or
more observations to NA. I think this will do the trick:

# assume the matrix or data frame is named "ajdat"
randomNA<-function(x,nNA=1) {
 dimx<-dim(x)
 x[sample(1:dimx[1],nNA),sample(1:dimx[2],nNA)]<-NA
 return(x)
}

So if you want three NAs inserted, call:

randomNA(ajdat,3)

Jim


On Fri, Jul 6, 2018 at 6:28 AM, Adam Z. Jabir <[hidden email]> wrote:

> Hi,
>
> I want to simulate missing at random for my dataset. Do you know an easy way to do it?
>
> I want to try not to have the missing’s for the same observations. I mean if one observation is been selected randomly to have missing I don’t want to have all the var of the same obs missing.
>
> I want to be able to choose rate of missing that should be applied.
>
> Thanks,
>
> Adam
>
>
> Envoyé à partir de Outlook<http://aka.ms/weboutlook>
>
>         [[alternative HTML version deleted]]
>
>
> ______________________________________________
> [hidden email] mailing list -- To UNSUBSCRIBE and more, see
> 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.
>

______________________________________________
[hidden email] mailing list -- To UNSUBSCRIBE and more, see
https://stat.ethz.ch/mailman/listinfo/r-help
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Re: command to change some vars to missing into my dataset

Bert Gunter-2
Jim/Rui:

Strictly speaking, this is wrong. What you have described is MCAR --
missing completely at random -- not MAR. They are different! Nevertheless,
the OP seems to be similarly confused about this, so MCAR may in fact be
what what  was wanted. Without further context, it is as clear as mud to me.

Cheers,
Bert



Bert Gunter

"The trouble with having an open mind is that people keep coming along and
sticking things into it."
-- Opus (aka Berkeley Breathed in his "Bloom County" comic strip )

On Thu, Jul 5, 2018 at 3:44 PM, Jim Lemon <[hidden email]> wrote:

> Hi Adam,
> Looks like you have a matrix or data frame and want to change one or
> more observations to NA. I think this will do the trick:
>
> # assume the matrix or data frame is named "ajdat"
> randomNA<-function(x,nNA=1) {
>  dimx<-dim(x)
>  x[sample(1:dimx[1],nNA),sample(1:dimx[2],nNA)]<-NA
>  return(x)
> }
>
> So if you want three NAs inserted, call:
>
> randomNA(ajdat,3)
>
> Jim
>
>
> On Fri, Jul 6, 2018 at 6:28 AM, Adam Z. Jabir <[hidden email]>
> wrote:
> > Hi,
> >
> > I want to simulate missing at random for my dataset. Do you know an easy
> way to do it?
> >
> > I want to try not to have the missing’s for the same observations. I
> mean if one observation is been selected randomly to have missing I don’t
> want to have all the var of the same obs missing.
> >
> > I want to be able to choose rate of missing that should be applied.
> >
> > Thanks,
> >
> > Adam
> >
> >
> > Envoyé à partir de Outlook<http://aka.ms/weboutlook>
> >
> >         [[alternative HTML version deleted]]
> >
> >
> > ______________________________________________
> > [hidden email] mailing list -- To UNSUBSCRIBE and more, see
> > 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.
> >
>
> ______________________________________________
> [hidden email] mailing list -- To UNSUBSCRIBE and more, see
> 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.
>

        [[alternative HTML version deleted]]

______________________________________________
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