[R] A matrix with mixed character and numerical columns

[Petr PIKAL]

r-help-bounces at stat.math.ethz.ch napsal dne 31.05.2007 14:32:01:

> What I am trying to do is create an x-y plot from the numerical values,
> and the output of row() or col() gives me an excellent way of
> calculating an x- or y- co-ordinate, with the value in the data.frame
> being the other half of the pair.
> 
> Thanks for the code, Petr - I'm sure you would agree, however, that it's
> a bit 'clumsy' (no fault of yours).
> 
> Can we just adjust row() and col() for data.frames?
> 
> col <- function (x, as.factor = FALSE)
> {
>     if (is.data.frame(x)) {
>       x <- as.matrix(x)
>     }
>     if (as.factor)
>         factor(.Internal(col(x)), labels = colnames(x))
>     else .Internal(col(x))
> }
> 
> row <- function (x, as.factor = FALSE) 
> {
>     if (is.data.frame(x)) {
>       x <- as.matrix(x)
>     }
>     if (as.factor) 
>         factor(.Internal(row(x)), labels = rownames(x))
>     else .Internal(row(x))
> }
> 
> Is there any reason why these won't work?  Am I oversimplifying it?

Seems to me that both works. At least on data.frame I tried it.

Regards
Petr

> 
> Mick
> -----Original Message-----
> From: Petr PIKAL [mailto:petr.pikal at precheza.cz] 
> Sent: 31 May 2007 12:57
> To: michael watson (IAH-C)
> Cc: r-help at stat.math.ethz.ch
> Subject: Odp: [R] A matrix with mixed character and numerical columns
> 
> Hi
> r-help-bounces at stat.math.ethz.ch napsal dne 31.05.2007 12:48:11:
> 
> > Is it possible to have one?
> > 
> > I have a data.frame with two character columns and 6 numerical
> columns.
> > 
> > I converted to a matrix as I needed to use the col() and row()
> > functions.
> > However, if I convert the data.frame to a matrix, using as.matrix, the
> > numerical columns get converted to characters, and that messes up some
> > of the calculations.
> > 
> > Do I really have to split it up into two matrices, one character and
> the
> > other numerical, just so I can use the col() and row() functions?  Are
> > there equivalent functions for data.frames?
> 
> AFAIK I do not remember equivalent functions for data frame. If you just
> 
> want column or row index you can use
> 
> 1:dim(DF)[1] or 1:dim(DF)[2] for rows and columns
> 
> if you want repeat these indexes row or columnwise use
> 
> rrr<-rep(1:dim(DF)[1], dim(DF)[2])
> matrix(rrr,dim(DF)[1], dim(DF)[2])
> 
> rrr<-rep(1:dim(DF)[2], dim(DF)[1])
> matrix(rrr,dim(DF)[1], dim(DF)[2], byrow=T)
> 
> Regards
> Petr
> 
> 
> 
> > 
> > ______________________________________________
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> 
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> PLEASE do read the posting guide 
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> and provide commented, minimal, self-contained, reproducible code.