| topbottom {inaparc} | R Documentation |
Initialization of cluster prototypes using the top and bottom objects
Description
Initializes the cluster prototypes matrix using the alternately selected k objects from the top and bottom of the data set.
Usage
topbottom(x, k)
Arguments
x |
a numeric vector, data frame or matrix. |
k |
an integer for the number of clusters. |
Details
The function combines the firstk and lastk techniques. It takes the first object of the data set as the prototype of first cluster, and then the last object as the prototype of second cluster. This rotating assigment process continues until the prototypes of k clusters are assigned.
Value
an object of class ‘inaparc’, which is a list consists of the following items:
v |
a numeric matrix containing the initial cluster prototypes. |
ctype |
a string representing the type of centroid, which used to build prototype matrix. Its value is ‘obj’ with this function because the cluster prototype matrix contains the objects. |
call |
a string containing the matched function call that generates this ‘inaparc’ object. |
Note
If the sorted data set is used, the function topbottom may yield better initializations when compared to the functions firstk and lastk.
Author(s)
Zeynel Cebeci, Cagatay Cebeci
See Also
aldaoud,
ballhall,
crsamp,
firstk,
forgy,
hartiganwong,
inofrep,
inscsf,
insdev,
kkz,
kmpp,
ksegments,
ksteps,
lastk,
lhsmaximin,
lhsrandom,
maximin,
mscseek,
rsamp,
rsegment,
scseek,
scseek2,
ssamp,
spaeth,
uniquek,
ursamp
Examples
data(iris)
res <- topbottom(x=iris[,1:4], k=5)
v <- res$v
print(v)