merge table rows (\multirow)

Hi:
This is what my table should look like:

Month     Week   Estpassage    MedFL
July-----27--------4566--------34
   -----28--------2568--------35
   -----29--------3287--------36
   -----30--------4623--------37
Aug------31--------8632--------37
  ------32--------4236--------38
  ------33--------7632--------39
  ------34--------5984--------40
Sept-----35--------1258--------40
   -----36--------4235--------41
   -----37--------2573--------42
   -----38--------423---------43
I don't want to reshape my dataset, I basically want a latex table showing only one value on the first column instead of repeating the  month over and over. I know this can be done with \multirow if the table is created manually. Since this table is created dynamically on the fly I don't know how to use \multirow like that. Hope is clear. Thanks


--- On Mon, 1/12/09, Dieter Menne <dieter.menne at menne-biomed.de> wrote:

From: Dieter Menne <dieter.menne at menne-biomed.de>
Subject: Re: [R] merge table rows (\multirow)
To: r-help at stat.math.ethz.ch
Date: Monday, January 12, 2009, 12:41 AM
Felipe Carrillo <mazatlanmexico <at> yahoo.com>
writes:

I need help merging rows.
I am trying to merge the 'Month' column using

\multirow. For example for the
column 'Week' I want July to be

merged into one row(weeks 27,28,29,30) and so on for

the following weeks.

Below, I am creating a PDF using Sweave,

MikTex,R-2.8.1 and windows XP to show
an example.


I don't fully understand how the table should look
like, mainly
how the Week display should look like. I suggest that you
try to
not do the main formatting in latex/xtable, but rather use
function reshape or package reshape (below). The following
should give you a starter, I know it is not fully what you
want.

Dieter


sampDat <- "Month Week Estpassage MedFL
July 27       665             34
July 28       2232           35
July 29       9241           35
July 30       28464           35
Aug  31       41049           35
Aug 32       82216           35
Aug 33       230411      35
Aug 34       358541      35
Sept 35       747839      35
Sept 36       459682      36
Sept 37       609567      36
Sept 38       979475      36
Sept 39       837189      36"
DF <- read.table(textConnection(sampDat), header = TRUE)

library(reshape)
DFm = melt(DF,id=c("Month","Week"))
cast(DFm,variable~Month+Week)