Table 4 Optimized parameters of ANFIS, RSA, GWO, and WOA models.

From: Integration of the reptile search algorithm and the adaptive neuro-fuzzy inference system enhances standardized precipitation evapotranspiration index forecasting

Model

Parameter

Value

ANFIS

Fuzzy structure

Sugeno- type

Initial FIS for training

Genfis3

The type of membership functions

Gaussian

The membership function of output

Linear

Optimization method

Hybrid

Number of fuzzy rules

8

The maximum number of epochs

1000

RSA

Population size

30

Iteration number

1000

Beta (β)

0.10

Alfa (α)

0.15

WOA

a

2–0

r

min = 0 and max = 1

Iterations number

1000

Population size

30

GWO

a

2–0

r

min = 0 and max = 1

Iterations number

1000

Population size

30