Last active
December 2, 2018 07:16
-
-
Save tkazusa/be15f0994b2f03cabbd2de2ef5d58f1a to your computer and use it in GitHub Desktop.
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
def negative_down_sampling(data, random_state, target_variable): | |
positive_data = data[data[target_variable] == 1] | |
positive_ratio = float(len(positive_data)) / len(data) | |
negative_data = data[data[target_variable] == 0].sample( | |
frac=positive_ratio / (1 - positive_ratio), random_state=random_state) | |
return pd.concat([positive_data, negative_data]) | |
def multi_class_downsampling(data, random_state, target_variable): | |
data0 = data[data[target_variable] == 0] | |
data1 = data[data[target_variable] == 1] | |
data2 = data[data[target_variable] == 2] | |
data3 = data[data[target_variable] == 3] | |
data0_ratio = float(len(data0)) / len(data) | |
data1_ratio = float(len(data1)) / len(data) | |
data2_ratio = float(len(data2)) / len(data) | |
data3_ratio = float(len(data3)) / len(data) | |
data0_sampled = data[data[target_variable] == 0].sample( | |
frac=data3_ratio / data0_ratio, random_state=random_state) | |
data1_sampled = data[data[target_variable] == 1].sample( | |
frac=data3_ratio / data1_ratio, random_state=random_state) | |
data2_sampled = data[data[target_variable] == 2].sample( | |
frac=data3_ratio / data2_ratio, random_state=random_state) | |
return pd.concat([data0_sampled, data1_sampled, data2_sampled, data3]) |
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment