Dissimilarity Matrix Object
- DESCRIPTION:
-
These are objects of class
"dissimilarity"
They represent the dissimilarity matrix of a dataset.
- GENERATION:
-
daisy returns this class of objects.
When provided with "observations by variables" input, also the functions
pam, clara and fanny return a dissimilarity object, as one component
of their return objects.
- METHODS:
-
The "dissimilarity" class has methods for the following generic functions:
print.
- STRUCTURE:
-
The dissimilarity matrix is symmetric, and hence is represented as a vector
to save storage space.
For i less than j, the dissimilarity between row i and row j is element
nrow(x)*(i-1) - i*(i-1)/2 + j-i of that vector.
The length of the vector is nrow(x)*(nrow(x)-1)/2,
that is, it is of order nrow(x) squared.
The object has the following attributes:
- Size:
-
the number of objects in the dataset.
- Metric:
-
the metric used for calculating the dissimilarities. Possible values are
"euclidean", "manhattan", "mixed" (if variables of different types were
present in the dataset), and "unspecified".
- Labels:
-
optionally, contains the labels, if any, of the objects of the dataset.
- NA.message:
-
optionally, if a dissimilarity could not be computed, because of too many
missing values for some objects of the dataset.
- SEE ALSO:
-
clara
,
daisy
,
dist
,
fanny
,
pam
.