# grid search result max_features = 'sqrt' in random forest - how to understand

I did a grid search at random forest params. the result of

print(randomforestreg.best_params_)


The result is = {'max_depth': 28, 'n_estimators': 500 ',max_features': 'sqrt', 'min_samples_split': 2, 'min_samples_leaf': 1'}

The Random Forest documentation: If “auto”, then max_features=sqrt(n_features). If “sqrt”, then max_features=sqrt(n_features) (same as “auto”).

So 'sqrt' is like max_features=sqrt(n_features) --> same as 'auto'. --> the number of features with which tree is build. I dont understand this. When I have 19 columns(features) and 100.000 rows, what is now the answer of the question; "what is the best value for max_features?". Is it the squared value of n features = 19^2 = 361?

• "sqrt" is a standard abbreviation of "square root" Oct 5, 2020 at 1:01