dissimilarity.object: Dissimilarity Matrix Object
Description
Objects of class "dissimilarity"
representing the dissimilarity
matrix of a dataset.
Value
The dissimilarity matrix is symmetric, and hence its lower triangle
(column wise) is represented as a vector to save storage space.
If the object, is called do
, and n
the number of
observations, i.e., n <- attr(do, "Size")
, then
for $i < j <= n$,="" the="" dissimilarity="" between="" (row)="" i="" and="" j="" is="" do[n*(i-1) - i*(i-1)/2 + j-i].
The length of the vector is $n*(n-1)/2$, i.e., of order $n^2$."dissimilarity"
objects also inherit from class
dist
and can use dist
methods, in
particular, as.matrix
, such that $d(i,j)$
from above is just as.matrix(do)[i,j]
.The object has the following attributes:=>
GENERATION
daisy
returns this class of objects.
Also the functions pam
, clara
, fanny
,
agnes
, and diana
return a dissimilarity
object,
as one component of their return objects.METHODS
The "dissimilarity"
class has methods for the following generic
functions: print
, summary
.