Evaluate prediction from multiple classification model

Question

Given that I have data containing images of oranges, apples and pineapples and I want to classify depending on a set of features.

Expected that I have completed the model and ready for prediction.

My questions are:

How can I output each score for every category the model predicted like this one?

Image 1:
     60% apple, 20% orange, 1% pineapple
     It implies that the image is an apple.


Image 2:
     40% apple, 60% orange, 10% pineapple
     It implies that the image is an orange.

Is there any libraries I can use with?

Does it depend on the model I am using? If yes, what are these models that implement this evaluation?

Answer 1

Based on the description of your question, it seems that you want the probability of outcome of each class (in multiclass-classification).

I would suggest you to use XGBoost to get output based on your requirement. By setting the value of objective parameter to multi:softprob, you can get probability of prediction of each and every class. If you set the value of objective parameter to multi:softmax, then you will only get the class with maximum probability among other classes.

Here, I am writing a example for your reference and to explain this description in a better way. You can get output by printing y_test_preds.

import xgboost as xgb

xgb_class = xgb.XGBClassifier(**params)
bst = xgb.train(params, dtrain, num_rounds)
y_test_preds = bst.predict(dtest)

By the following way, you can set the parameters for XGBoost. I would strongly suggest you to modify these parameters (except objective) based on your data and requirements.

params = {
     'objective' : 'multi:softprob',
     'max_depth' : 6,
     'silent' : 1,
     'eta' : 0.4,
     'num_class' : 3,
     'n_estimators' : 500,
     'learning_rate' : 0.1,
     'num_rounds' : 15
}

Note: In XGBoost, you have to use DMatrix instead of DataFrame. You can also get the DMatrix from DataFrame by this way.

dtrain = xgb.DMatrix(X_train.values, label = y_train.values)
dtest = xgb.DMatrix(X_test.values, label = y_test.values)

If you are new to XGBoost, then I would recommend you to go through this link once. https://xgboost.readthedocs.io/en/latest/get_started.html