rollmin in R similar to zoo package rollmax

Question

Is there a function for rollmin in the same way rollmean and rollmax work from the zoo package? I've looked into the zoo help document but can't find anything.

Answer 1

Run rollmax on the negative of the values and then negate the result. For example,

library(zoo)

 x <- 1:10

-rollmaxr(-x, 3, fill = NA)
## [1] NA NA  1  2  3  4  5  6  7  8

Another possibility is to use rollapply with the min function:

rollapplyr(x, 3, min, fill = NA)
## [1] NA NA  1  2  3  4  5  6  7  8

Answer 2

We can use roll_min from library(RcppRoll) the usage is

roll_min(x, n = 1L, weights = NULL, by = 1L, fill = numeric(0),
partial = FALSE, align = c("center", "left", "right"), normalize = TRUE, na.rm = FALSE)

eg

roll_min(1:10, 3, fill = NA, align = "right")
#[1] NA NA  1  2  3  4  5  6  7  8