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")]]