unname(obj, force = FALSE)
| obj | an object for which you want to remove the names or dimnames. |
| force |
a logical value.
If TRUE, dimnames are always removed, even if obj is a data frame.
If FALSE (the default), dimnames are removed only when obj is
not a data frame. (obj can be a matrix, an array, or other object
type.)
This argument does not affect the names of an object. |
x <- c(1:12) names(x) <- as.character(1:12) unname(x)
x <- array(runif(24), c(2, 4, 3), list(c("r1","r2"), c("c1", "c2", "c3", "c4"), c("s1", "s2", "s3"))) unname(x)
# data frame x <- as.data.frame(matrix(runif(20), 5, 4))
# error, dimnames of data frame can't be null unname(x, force = TRUE) unname(x) # the column names are removed.
# Some calculations are substantially faster if you remove names # from input vectors first. z1 <- runif(1000) names(z1) <- as.character(1:1000)
# sys.time is used system.time(for(i in 1:1000) z1[i] <- z1[i]) z1 <- unname(z1)
# sys.time is used system.time(for(i in 1:1000) z1[i] <- z1[i])