[R] Reverse the scoring of some Columns of a Data Set

[Nordlund, Dan (DSHS/RDA)]

Another alternative (which didn't work last night when I was tired and obviously doing something wrong) is to use the built-in function, rev():

df[,1:3] <- apply(df[,1:3], 2, rev)


Dan

Daniel Nordlund, PhD
Research and Data Analysis Division
Services & Enterprise Support Administration
Washington State Department of Social and Health Services

> -----Original Message-----
> From: R-help [mailto:r-help-bounces at r-project.org] On Behalf Of Daniel
> Nordlund
> Sent: Wednesday, March 08, 2017 11:35 PM
> To: AbouEl-Makarim Aboueissa; r-help at r-project.org
> Subject: Re: [R] Reverse the scoring of some Columns of a Data Set
> 
> On 3/8/2017 6:14 AM, AbouEl-Makarim Aboueissa wrote:
> > Dear All: goods morning
> >
> > Is there is a way to reverse the scoring of the first three columns
> x1, x2,
> > and x3 and keep the original scores for the fourth column x4.
> >
> >
> > *Here is an example of the data set:*
> >
> > x1 x2 x3 x4
> > 2  5   4   4
> > 1  1   1   6
> > 1  2   1   6
> > 2  3   2   4
> > 1  2   1   6
> > 1  3   1   6
> > 2  2   2   5
> > 2  1   1   6
> > 2  2   4   5
> > 5  5   2   1
> >
> > I am expecting the output to be:
> > x1 x2 x3 x4
> > 5  5   2   4
> > 2  2   4   6
> > 2  1   1   6
> > 2  2   2   4
> > 1  3   1   6
> > 1  2   1   6
> > 2  3   2   5
> > 1  2   1   6
> > 1  1   1   5
> > 2  5   4   1
> >
> >
> >
> > thank you very much for your help and support
> > abou
> > ______________________
> > AbouEl-Makarim Aboueissa, PhD
> > Department of Mathematics and Statistics
> > University of Southern Maine
> >
> 
>   If your data is in a data frame called df, you could do something like
> this:
> 
> df[,1:3] <- apply(df[,1:3], 2, function(x) x[length(x):1])
> 
> 
> Hope this helps,
> 
> Dan
> 
> --
> Daniel Nordlund
> Port Townsend, WA  USA
> 
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