Re: [R] Class attributes
On Dec 4, 2009, at 11:55 AM, Allen L wrote:
Dear R forum,
I want to replace all the elements in a data frame (dd) which match
the
character "x" with "0".
What's the most elegant way of doing this (there must be an easy way
which
I've missed)? I settled on the following loop:
for(i in 5:12){# These are the column of dd I am
interested
in
dd[which(dd[,i]=="x"),i]<-0
}
The problem with this is that the columns which used to contain "x"
are
still considered factors and I am unable to coerce them into numeric:
Converting the labels of fac.obj (a factor object) to numeric values
is a FAQ (I forget the number, 7.)
as.numeric(as.character( fac.obj ))
Factors are internally sets of numbers, but those numbers are not
generally what people assign meaning to, and certainly not in your
case where you assigned the character "0" to those rows where the
labels were previously "x".
mean.species.biomass<-colMeans(as.numeric(dd.p[,5:12]))
Error in inherits(x, "data.frame") :
(list) object cannot be coerced to type 'double'
I'm tried unclassing & reclassing, other functions etc. but nothing
seems to
work. What is wrong?
Thanks in advance,
Allen
--
--
David Winsemius, MD
Heritage Laboratories
West Hartford, CT
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Re: [R] Class attributes
Here a way of doing it:
for (i in 5:12){
# convert to character so you can substitute 'x'
a <- as.character(dd[,i])
a[a == 'x'] <- '0' replace with zero
dd[,i] <- as.numeric(a)
}
On Fri, Dec 4, 2009 at 11:55 AM, Allen L wrote:
>
> Dear R forum,
> I want to replace all the elements in a data frame (dd) which match the
> character "x" with "0".
> What's the most elegant way of doing this (there must be an easy way which
> I've missed)? I settled on the following loop:
>
> >for(i in 5:12){# These are the column of dd I am
> interested
> in
> >dd[which(dd[,i]=="x"),i]<-0
> >}
>
> The problem with this is that the columns which used to contain "x" are
> still considered factors and I am unable to coerce them into numeric:
>
> > mean.species.biomass<-colMeans(as.numeric(dd.p[,5:12]))
> >Error in inherits(x, "data.frame") :
> (list) object cannot be coerced to type 'double'
>
> I'm tried unclassing & reclassing, other functions etc. but nothing seems
> to
> work. What is wrong?
> Thanks in advance,
> Allen
> --
> View this message in context:
> http://n4.nabble.com/Class-attributes-tp948693p948693.html
> Sent from the R help mailing list archive at Nabble.com.
>
> __
> R-help@r-project.org 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.
>
--
Jim Holtman
Cincinnati, OH
+1 513 646 9390
What is the problem that you are trying to solve?
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R-help@r-project.org mailing list
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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.
[R] Class attributes
Dear R forum,
I want to replace all the elements in a data frame (dd) which match the
character "x" with "0".
What's the most elegant way of doing this (there must be an easy way which
I've missed)? I settled on the following loop:
>for(i in 5:12){# These are the column of dd I am interested
in
>dd[which(dd[,i]=="x"),i]<-0
>}
The problem with this is that the columns which used to contain "x" are
still considered factors and I am unable to coerce them into numeric:
> mean.species.biomass<-colMeans(as.numeric(dd.p[,5:12]))
>Error in inherits(x, "data.frame") :
(list) object cannot be coerced to type 'double'
I'm tried unclassing & reclassing, other functions etc. but nothing seems to
work. What is wrong?
Thanks in advance,
Allen
--
View this message in context:
http://n4.nabble.com/Class-attributes-tp948693p948693.html
Sent from the R help mailing list archive at Nabble.com.
__
R-help@r-project.org 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.
