[R] How to get Quartiles when data contains both numeric variables and factors

[R. Michael Weylandt]

Just add something to skip the non-numeric variables:

e.g.,

lapply(x, function(x) if(is.numeric(x)) quantile(x,c(0.01, 0.99)) else
levels(x))

If you want to use sapply(), you'll need the factor case to return
something that is 2x1 so it can all be simplified nicely.

Michael

On Mon, Oct 31, 2011 at 9:09 AM, aajit75 <aajit75 at yahoo.co.in> wrote:
> When data contains both factor and numeric variables, how to get quartiles
> for all numeric variables?
> n <- 100
> x1 <- runif(n)
> x2 <- runif(n)
> x3 <- x1 + x2 + runif(n)/10
> x4 <- x1 + x2 + x3 + runif(n)/10
> x5 <- factor(sample(c('a','b','c'),n,replace=TRUE))
> x6 <- factor(1*(x5=='a' | x5=='c'))
> data1 <- cbind(x1,x2,x3,x4,x5,x6)
> data <- data.frame(data1)
>
> data <- within(data,{x5 <- factor(x5)})
> x <- data
>
> qs <- sapply(x, function(x) quantile(x, c(0.01, 0.99)))
>
> I get an error: Error in quantile.default(x, c(min_pct, max_pct)) : factors
> are not allowed
>
> Thanks for the help.
>
>
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