Table 2 Optimization hyper-parameters of different model for tuning the developed CP-EGBM.

From: An efficient churn prediction model using gradient boosting machine and metaheuristic optimization

Model

Function

Default value

Search space

SVMRBF

\(\mathrm{C}\)

1

LB: 1E−1, UB: 1E

Mapping of the feature space (\(\gamma\))

1/(#features)

LB: 1E−4, UB:1E4

GBM

Number of estimators

100

LB: 100, UB:3000

Learning rate

0.1

LB: 1E−3, UB:1

Maximum depth of DTs

3

LB: 1, UB: 10

Minimum samples for split

2

LB: 2, UB: 10

Maximum features

Sqrt(#features)

LB: 1, UB: #features

Sub-sample

1

LB: 0.5, UB:1

  1. LB lower boundary, UB upper boundary.