How can I convert a LightGBM model to ONXX?

Question

I'm trying to save my model so it can be used in a ASP.NET program, and I think that ONNX is a good way to do so. The problem is that even after checking the docs and googling it all day, I still get the same error raise ValueError('Initial types are required. See usage of ' ValueError: Initial types are required. See usage of convert(...) in skl2onnx.convert for details. I have no idea what's going on and any help is greatly appreciated!

My Code

import onnxmltools
from skl2onnx import convert
import lightgbm as lgb
import pandas as pd

parameters = {
    'boosting': 'gbdt',
    'feature_fraction': 0.5,
    'bagging_fraction': 0.5,
    'bagging_freq': 20,
    'num_boost_round': 10000,
    'verbose': -1 #maybe?
}


model_lgbm = lgb.train(parameters, train_data, valid_sets = test_data, early_stopping_rounds = 200);

onnx_model = convert.convert_sklearn(model_lgbm, ???);

Answer 1

I think this doc will help you.

You have to use : onnxmltools.convert_lightgbm and not convert.convert_sklearn