Tpot: why my cv score is negative number?

[iWangLin]

my code
from tpot import TPOTRegressor
from sklearn.datasets import load_boston
from sklearn.model_selection import train_test_split

housing = load_boston()
X_train, X_test, y_train, y_test = train_test_split(housing.data, housing.target,
train_size=0.75, test_size=0.25)

tpot = TPOTRegressor(generations=5, population_size=50, verbosity=2)
tpot.fit(X_train, y_train)
print(tpot.score(X_test, y_test))
tpot.export('tpot_boston_pipeline.py')

but the cv score is negative number as this:

I really want to know why?
Thank You!

[weixuanfu]

Please check this same issue #595

[weixuanfu]

Also #675

[weixuanfu]

I close this issue. Please feel free to re-open the issue if you have any more questions

[iWangLin]

Thank you. I checked the two same issues, but I have not clearly known about the Tpot Regressor. The value of cv socre should be negative ? Could you tell me where I can find the cv score of Tpot Regressor ？

[weixuanfu]

Related issue #425 #612

Please check TPOT API, the default scoring function is accuracy for TPOTClassifier, which is in range from 0 to 1. But it is neg_mean_squared_error for TPOTRegressor that stands for negated value of mean squared error.

[iWangLin]

Oh, I see. Thank you very much !