Table 2.

Parameters used for C-Cuckoo.

N	Population of cuckoos
M	Number of pseudo time steps
Pa	Discovery rate of alien eggs
Tol	Tolerance
K	Number of groups (clusters)
S	Number of samples
D	Number of attributes
w(s, k)	The element in matrix [s, k] where s ∈ S, k ∈ K
	$w_{s,k}=\{\begin{array}{cc}\mathrm{1},\hfill & x_s\in {\text{cluster}}_k\hfill \\ \mathrm{0},\hfill & x_s\notin {\text{cluster}}_k\hfill \end{array}$
x(i, j)	The best solution in matrix [i, j] where i ∈ N, j ∈ K ⊗ D
Cen(k, d)	The centroid in matrix [k, d] where k ∈ K, d ∈ K ⊗ D
Clmat(n, s)	The classification matrix [n, s] where n ∈ N, s ∈ S

Pa and Tol are conditional variables used for controlling execution of the cuckoo optimization algorithm [9].