wback of the K-means algorithm by introducing the soft
hip function to a clustering process [Dunn, 1973; Bezdek, 1981].
re of a cluster is defined as below, where ݂ሺܠሻ∈ሾ0,1ሿ is a soft
hip function measuring the degree by which the nth data point ܠ
o the kth cluster whose centre is ࢛,
࢛ൌ
∑
ሾ݂ሺܠሻሿܠ
ே
ୀଵ
∑
ሾ݂ሺܠሻሿ
ே
ୀଵ
(2.24)
e above definition, m is a positive parameter to weight the
hip. The membership ݂ሺܠሻ (for the nth data point ܠ to belong
cluster) is defined as below,
݂ሺܠሻൌቆ
‖ܠെ࢛‖
‖ܠെ࢛‖ቇ
ଶ
ିଵ
ୀଵ
(2.25)
ame as the K-means algorithm, the fuzzy C-means algorithm also
s model parameters (cluster centres ࢛) using random values.
n the initialised cluster centres, the algorithm estimates the
hips for each data point, i.e., ݂ሺܠሻ. Afterwards, the centres are
These two calculations are repeated until the maximum cycles
ed or the cluster centres stop to change.
use of the use of the soft membership function, the fuzzy C-means
m benefits from a slightly higher accuracy for dealing with a more
ted cluster model. In biological/medical pattern analysis, the
means algorithm has been integrated into a linear model which
o a significant improvement of the discovery accuracy of Type 1
based on blood glucose data [Montaser, et al., 2020]. It has also
d to cluster tissues in a computer-aided diagnosis of Alzheimer's
Lazli, et al., 2020].
R package for the fuzzy C-means algorithm is ppclust. The
unction for constructing a fuzzy C-means model is fcm, which is
s
fcm(x,centers, ⋯)