[R] Lattice: vertical barchart

[Sundar Dorai-Raj]

Michael Hoffman said the following on 7/10/2007 7:06 AM:
> barchart(Titanic, stack=F) produces a very nice horizontal barchart. 
> Each panel has four groups of two bars.
> 
> barchart(Titanic, stack=F, horizontal=F) doesn't produce the results I 
> would have expected, as it produces this warning message:
> 
> Warning message:
> y should be numeric in: bwplot.formula(x = as.formula(form), data = 
> list(Class = c(1,
> 
> And it results in each panel having 22 groups of 0-2 bars.
> 
> How can I produce something just like the original except with the 
> orientation changed?
> 
> Thanks in advance.
> 

Hi, Michael,

It seems that barchart.table doesn't allow the horizontal = FALSE 
argument. With a slight modification to barchart.table this can be 
accomplished. Also, I don't get a warning with your original code using 
R-2.5.1 and lattice 0.16-1.

HTH,

--sundar

barchart.table <-
function (x, data = NULL, groups = TRUE, origin = 0, stack = TRUE,
     horizontal = TRUE, ...) ## add horizontal argument
{
     formula <- x
     ocall <- sys.call(sys.parent())
     if (!is.null(data))
         warning("explicit 'data' specification ignored")
     data <- as.data.frame(formula)
     nms <- names(data)
     freq <- which(nms == "Freq")
     nms <- nms[-freq]

     ## SD: change formula if horizontal == FALSE
     form <- if(horizontal) {
       paste(nms[1], "Freq", sep = "~")
     } else {
       paste("Freq", nms[1], sep = "~")
     }
     ## SD: end change

     nms <- nms[-1]
     len <- length(nms)
     if (is.logical(groups) && groups && len > 0) {
         groups <- as.name(nms[len])
         nms <- nms[-len]
         len <- length(nms)
     }
     else groups <- NULL
     if (len > 0) {
         rest <- paste(nms, collapse = "+")
         form <- paste(form, rest, sep = "|")
     }
     ans <- barchart(as.formula(form), data, groups = eval(groups),
         origin = origin, stack = stack, ...)
     ans$call <- ocall
     ans
}


barchart(Titanic, stack = FALSE)
barchart(Titanic, stack = FALSE, horizontal = FALSE)