| subset.dist {cba} | R Documentation |
This function conveniently returns a subset (submatrix) of an object of class dist.
## S3 method for class 'dist': subset(x, subset, ...) ## S3 method for class 'dist': x[[subset, ...]] x[[i]]
x |
an object of class dist |
subset, i |
logical, character, or index vector |
... |
other (unused) arguments |
For consistency, subsetting a symmetric matrix is constrained to a single index (vector). However, non-unique indexing is allowed. In this case zero is returned for diagonal elements.
If x has a Labels attribute a character vector can
be used for subsetting.
Note that objects which contain diagonal elements are not handled.
An object of class dist.
This is experimental code which may change in future releases.
Christian Buchta
dist for details
x <- as.dist(matrix(1:36, ncol=6))
subset(x, c(2,4,6))
subset(x, c(4,2,6)) # same set but different order
attr(x, "Labels") <- letters[1:6] # hack!
subset(x, c(2,4,6))
subset(x, letters[c(2,4,6)])
subset(x, c(2,2,4,6)) # contains one zero
# this is more user friendly
x[[c(2,4,6)]]
x[[c("b","d","e")]]