Bayesian Optimization of RandomForest parameters, with scikit-learn, to be used in KNIME in Python learner node. Based on https://github.com/fmfn/BayesianOptimization/ by fmfn.

Prerequisities:

• pip install bayesian-optimization

Why?

1. Parameter Optimization Loop Node(s) doesn't work as expected for some data. Including Bayesian optimization.
2. You may want to use scikit-learn instead of KNIME or Weka implementation.
3. You can tune this workflow to optimize other parameters for many different scikit algorithms.

• In python node please select python2.
• copy&paste the python code into the code window of Python Learner (python-learner.py) and Python Predictor (python-predictor.py)
• sample workflow:

• in the input table, the class should be in the last column
• fine tuning - edit variables at the top of the python-learner.py:

#
# Bounded region of parameter space
#

parameterDict = { 'n_estimators': (100, 1200),
            'max_depth': (5, 30),
            'min_samples_split': (2, 100),
            'min_samples_leaf': (1, 10)
            }

#
# bayesian configuration
#

init_points = 5
n_iter = 20

• please note: scripts (after slight modifications) can be run from the command line
• sample data file provided (nr-ahr-lite.csv from my tox21 dataset)

Among some training progress data (static) info about best parameters found is displayed:

Best params: {'min_samples_split': 2, 'n_estimators': 205, 'max_depth': 30, 'min_samples_leaf': 1}
Best target value: 0.837006427916