On Jun 29, 2010, at 10:08 AM, Ottorino-Luca Pantani wrote: > Dear R-users, > please consider the following minimal example: > > \documentclass[a4paper,titlepage,onecolumn,12pt]{article} > \usepackage[italian]{babel} > \usepackage{amssymb} > \usepackage[utf8x]{inputenc} > \usepackage[pdftex]{graphicx} > \begin{document} > > <<label=test, echo=FALSE, results=tex>>= > df.data1 <- > cbind.data.frame(A = rnorm(18), > B =factor(rep(LETTERS[1:6], each=3))) > myMean <- tapply(df.data1$A, df.data1$B, FUN = mean) > mySD <- tapply(df.data1$A, df.data1$B, FUN = sd) > foo <- matrix(c(myMean, mySD), ncol=2, nrow=6) > colnames(foo) <- c("Mean", "Std.Dev") > tmpTable <- xtable(foo, caption ="Simulated data", > label="tab:four", digits=2) > print(tmpTable, caption.placement="top") > @ > > \end{document} > > Is it possible to insert the plus/minus sign (±) between the two columns ? > I mean within R/Sweave and not in the resulting .tex file ? > > A possible workaround could be : > ....... > foo.df <- as.data.frame(foo) > foo.df$Std.Dev <- paste("±", round(mySD,2), sep="") > tmpTable <- xtable(foo.df, caption ="Simulated data", > label="tab:five", digits=2) > print(tmpTable, caption.placement="top") > @ > > Any other solution?
Don't use "±" as the character, as that will be impacted upon by various issues, such as locale and fonts. Use the available LaTeX symbols, which in this case is \pm. See: http://www.ctan.org/tex-archive/info/symbols/comprehensive/symbols-letter.pdf In the case of this symbol, you need to put LaTeX into math mode by using '$' to surround the symbol: $\pm$ However, with R, you need to double the backslashes, otherwise the backslash will be interpreted as an escape sequence. Thus, you need: $\\pm$ So, for example: > paste("$\\pm$", 1.34, sep="") [1] "$\\pm$1.34" I believe you then need to tweak the sanitize.text.function argument in print.xtable() to properly handle the backslashes. HTH, Marc Schwartz ______________________________________________ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.