RE: [R] Q: changing the class of an object

From: Berton Gunter <>
Date: Fri 27 May 2005 - 02:48:49 EST

Datadrames don't have "cells" -- class, type, etc. is determined on a column by column basis (which is the same as a component by component basis, since datframes are also lists) Please read "An Introduction to R" before proceeding and posting so that you understand R's basic data structures and conventions.

BTW -- what do you have against for loops? One should vectorize calculations whenever possible,of course, but for loops are often useful and essentially instantaneous.

"The business of the statistician is to catalyze the scientific learning process." - George E. P. Box    

> -----Original Message-----
> From:
> [] On Behalf Of Dave Evens
> Sent: Thursday, May 26, 2005 9:31 AM
> To:
> Subject: [R] Q: changing the class of an object
> Dear All,
> I have a list of dataframes, each cell in every
> dataframe (after I have cleaned up the dataframes) is
> either real or NA but have class character (I think).
> I would like to know how to change the class of every
> cell without using a for-loop. I currently have this
> dataframes <- sapply(1: no.of.subs, function(k)
> apply(dataframes[[k]], 2, function(x) {
> if(class(x)=="character") x <- as(x, "numeric"); x }))
> but this neither changes the cells to numeric nor
> keeps the dataframes in a list.
> It creates one dataframe with number of rows=(no of
> rows in a dataframe*no of colums) and number of
> columns = no.of.subs
> Can someone please help? Thanks in advance for any
> help.

> Dave
> ______________________________________________
> mailing list
> PLEASE do read the posting guide!
> mailing list PLEASE do read the posting guide! Received on Fri May 27 02:52:34 2005

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