Multiclass Classification with LightGBM

Try troubleshooting by swapping classes 0 and 2, and re-running the trainining and prediction process.

If the new predictions only contain classes 1 and 2 (most likely given your provided data):

• Classifier may not have learnt the third class; perhaps its features overlap with those of a larger class, and the classifier defaults to the larger class in order to minimise the objective function. Try providing a balanced training set (same number of samples per class) and retry.

If the new predictions do contain all 3 classes:

• Something went wrong in your code somewhere. More information is needed to determine what exactly went wrong.

Hope this helps.