How does one remove columns either by name ("Exp1", "Exp2",
"Exp3", ...
"Exp100") or by column number from a matrix or data.frame using a list
of
names mynames =
("Exp10,"Exp20","Exp55","Exp67")
I would something in the form of (I know this does not work):
myMatrixEdited = myMatrix[,-mynames]
Or I would like to find the column numbers of the names in the list, and use
the column numbers to remove the columns in the matrix or data.frame.
Peter W.
Here are three ways:
subset(iris, select = -c(Sepal.Length, Species))
nm <- c("Sepal.Length", "Species")
iris[,!names(iris) %in% nm]
nm <- c("Sepal.Length", "Species")
iris[,setdiff(names(iris), nm)]
On 3/28/06, Peter Wilkinson <pwilkinson_m at xbioinformatics.org>
wrote:> How does one remove columns either by name ("Exp1",
"Exp2", "Exp3", ...
> "Exp100") or by column number from a matrix or data.frame using a
list of
> names mynames =
("Exp10,"Exp20","Exp55","Exp67")
>
> I would something in the form of (I know this does not work):
>
> myMatrixEdited = myMatrix[,-mynames]
>
> Or I would like to find the column numbers of the names in the list, and
use
> the column numbers to remove the columns in the matrix or data.frame.
>
>
> Peter W.
>
> ______________________________________________
> R-help at stat.math.ethz.ch mailing list
> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide!
http://www.R-project.org/posting-guide.html
>
Peter Wilkinson wrote:> How does one remove columns either by name ("Exp1", "Exp2", "Exp3", ... > "Exp100") or by column number from a matrix or data.frame using a list of > names mynames = ("Exp10,"Exp20","Exp55","Exp67") > > I would something in the form of (I know this does not work): > > myMatrixEdited = myMatrix[,-mynames]myMatrixEdited <- myMatrix[ , !(colnames(myMatrix) %in% mynames)] Uwe Ligges> > Or I would like to find the column numbers of the names in the list, and use > the column numbers to remove the columns in the matrix or data.frame. > > > Peter W. > > ______________________________________________ > R-help at stat.math.ethz.ch mailing list > https://stat.ethz.ch/mailman/listinfo/r-help > PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html