[R] Plotting counts vs. intervals for a shingle

[Deepayan Sarkar]

On Fri, May 8, 2009 at 1:30 PM, David Winsemius <dwinsemius at comcast.net> wrote:
>
> Took a bit of inspecting, looking at hidden functions, but this seems to do
> it:
>
> library(lattice)
>  a <- c(1:10, 5:10)
>  b <- cbind(c(0,2.5,4.5,6.5), c(5.5,7.5,9.5,11))
>  c <- shingle(a, b)
>  summary(c, showValues=FALSE)
>
> apply(as.matrix(levels(c)), 1, function(x) length(c[ c>= x[[1]][1] & c <=
> x[[1]][2] ]) )
>
> #[1]  6  8 10  8
>
> "apply" passes a list to the function which requires the "[[" operation
> before the index. Since you did not create an example that represents the
> exceptions, i did not test for any such conditions. (Why do people not
> construct proper examples?)

Noting that

> str(levels(c))
List of 4
 $ : num [1:2] 0 5.5
 $ : num [1:2] 2.5 7.5
 $ : num [1:2] 4.5 9.5
 $ : num [1:2] 6.5 11
 - attr(*, "class")= chr "shingleLevel"

I would suggest the slightly simpler

> sapply(levels(c), function(x) sum(x[1] <= c & c <= x[2]))
[1]  6  8 10  8

-Deepayan