R data.frame with stacked specified titles for latex output with xtable
> w<-data.frame(c(0,0,1,1.3,2.1), c(0,0.6,0.9,1.6091,1.6299), c(258,141,206.4,125.8,140.5), c(162,162.7,162.4,162,162))
> colnames(w) <- c('Worst Cum', 'Best Cum', 'Worst Points', 'Best Points' )
Wrong (the code)
Worst Cum Best Cum Worst Points Best Points
1 0.0 0.0000 258.0 162.0
2 0.0 0.6000 141.0 162.7
3 1.0 0.9000 206.4 162.4
4 1.3 1.6091 125.8 162.0
5 2.1 1.6299 140.5 162.0
Goal: how?
CUM Points
Worst Best Worst Best
1 0.0 0.0000 258.0 162.0
2 0.0 0.6000 141.0 162.7
3 1.0 0.9000 206.4 162.4
4 1.3 1.6091 125.8 162.0
5 2.1 1.6299 140.5 162.0
------------- Examples (needles to read further if you know the solution to the above) -------------
Trial 1: fail with many data.frames
> a<-data.frame(c(0,0,1,1.3,2.1), c(0,0.6,0.9,1.6091,1.6299))
> b<-data.frame(c(258,141,206.4,125.8,140.5), c(162,162.7,162.4,162,162))
> c<-data.frame(cbind(a,b))
> colnames(c) <- c('Cum', 'Points')
> colnames(a) <- c('Worst', 'Best')
> colnames(b) <- c('Worst', 'Best')
and
> xtable(c)
% latex table generated in R 2.13.1 by xtable 1.6-0 package
% Thu Nov 24 03:43:34 2011
begin{table}[ht]
begin{center}
begin{tabular}{rrrrr}
hline
& Cum & Points & NA & NA
hline
1 & 0.00 & 0.00 & 258.00 & 162.00
2 & 0.00 & 0.60 & 141.00 & 162.70
3 & 1.00 & 0.90 & 206.40 & 162.40
4 & 1.30 & 1.61 & 125.80 & 162.00
5 & 2.10 & 1.63 & 140.50 & 162.00
hline
end{tabular}
end{center}
end{table}
> xtable(a)
% latex table generated in R 2.13.1 by xtable 1.6-0 package
% Thu Nov 24 03:45:06 2011
begin{table}[ht]
begin{center}
begin{tabular}{rrr}
hline
& Worst & Best
hline
1 & 0.00 & 0.00
2 & 0.00 & 0.60
3 & 1.00 & 0.90
4 & 1.30 & 1.61
5 & 2.10 & 1.63
hline
end{tabular}
end{center}
end{table}
It is wrong because it replaces the inner headers with higher-level header nb "NA" vals.
The latex function from Hmisc package will do the trick. Here is the code (make sure to include usepackage{booktabs} in your preamble to get nicer table formatting)
library(Hmisc)
latex(w, file = "", booktabs = TRUE, title = "", cgroup = c('Cum', 'Points'),
colheads = rep(c('Worst', 'Best'), 2))