Color the column of a latex table produced by xtable

Question

How can I use the R xtable package to produce a table with a colored column? This post shows how to color a row, but I can't figure out how to do the same for columns.

Answer 1

Here is a code snipped that should clarify it. The key is to define a new column type. In this example Iused "a" for the name of the new column and assigned a medium gray to it:

\usepackage{xcolor, colortbl}
\definecolor{Gray}{gray}{0.85}
\newcolumntype{a}{>{\columncolor{Gray}}c}


<<xtable1, results=tex, echo=F>>=
xtab<-xtable(d, caption="...", label="tab.myData")
align(xtab) <- c('l', 'c', 'a')
print(xtab, floating=F, include.rownames = F)
@