[R] abbreviate dataframe for Sweave output

[Charles C. Berry]

Chris,

Not precisely what you want (does both rows and columns), but can be 
specialized to your case easily.

Use with xtable in a chunk with 'results=tex' as in

 	xtable( dot.matrix( diag(10) ) )

Chuck

dot.matrix <- function(x , rws=NULL, cls=NULL, in.math=FALSE )
{


   ## Purpose: prepare a matrix like object for xtable printing with
   ## embedded cdots and vdots to stand in for omitted rows and columns
   ## 
----------------------------------------------------------------------
   ## Arguments: x - a data.frame or matrix,
   ##            rws - rows to include , cls - cols to include ,
   ##            in.math - in math mode? dont use $
   ## 
----------------------------------------------------------------------
   ## Author: CCB, Date: 13 Jan 2007, 12:54

   if (length(rws)==1) {def.rows <- rws;rws <- NULL} else def.rows <- 2
   if (length(cls)==1) {def.cols <- cls;cls <- NULL} else def.cols <- 2

   if (in.math) {
     cdot <- "\\cdots"
     vdot <- "\\vdots"
     ddot <- "\\ddots"
   } else {
     cdot <- "$\\cdots$"
     vdot <- "$\\vdots$"
     ddot <- "$\\ddots$"
   }

   x <- as.data.frame(x)

   if (is.null(rws)) {
     rws <- rownames(x)
     if (is.null(rws)) rws <- seq(nrow(x))
     rws <- list(head=head(rws,def.rows),tail=tail(rws,def.rows))
   }
   if (is.null(cls)) {
     cls <- colnames(x)
     if (is.null(cls)) cls <- seq(ncol(x))
     cls <- list(head=head(cls,def.cols),tail=tail(cls,def.cols))
   }

   safe.dots <- structure(list(factor(cdot,c(cdot,ddot))),names=cdot,row.names=as.integer(1),class="data.frame")

   head.rows <- cbind( x[ rws$head, cls$head ,drop=FALSE ], safe.dots,
                      x[ rws$head, cls$tail ,drop=FALSE ])

   mid.row <- structure(matrix(rep(c(vdot,ddot,vdot),c(length(cls$head),1,length(cls$tail))),nr=1),
                        dimnames=list(vdot,colnames(head.rows)))

   tail.rows <- cbind( x[ rws$tail, cls$head ,drop=FALSE ], safe.dots, x[ rws$tail, cls$tail ,drop=FALSE ] )

   tab <- rbind(head.rows,mid.row,tail.rows)

   tab
}




On Tue, 6 Feb 2007, stubben wrote:

> I wanted to print the first and last rows of some dataframes in Sweave
> using dots in columns to separate the two parts.  Head and tail almost
> work, but I have problems with factors and row names.
>
> z<-data.frame(id=letters[1:26], x=sample(1:26,26))
>
> rbind(head(z,3), ".", tail(z,1))
>
>      id  x
> 1     a 18
> 2     b  8
> 3     c 14
> 4  <NA>  .
> 26    z 10
> Warning message:
> invalid factor level, NAs generated in...
>
>
> I would like something like this if possible.  Any ideas?
>
>      id  x
> 1     a 18
> 2     b  8
> 3     c 14
> .     .  .
> .     .  .
> 26    z 10
>
>
> Thanks,
>
> Chris Stubben
>
>
>
> -- 
> -----------------
>
> Los Alamos National Lab
> BioScience Division
> MS M888
> Los Alamos, NM 87545
>
> ______________________________________________
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> and provide commented, minimal, self-contained, reproducible code.
>

Charles C. Berry                        (858) 534-2098
                                          Dept of Family/Preventive Medicine
E mailto:cberry at tajo.ucsd.edu	         UC San Diego
http://biostat.ucsd.edu/~cberry/         La Jolla, San Diego 92093-0901