feature_selection.py 文件源码

def chi2_feature_test(X,y,feature_index):
    """
    Performs the chi square test on the desired feature

    Keyword arguments:
    X -- The feature vectors
    y -- The target vector
    feature_index - The selected feature (a zero-based index)
    """

    feature_column=X[:,feature_index].reshape(-1,1)
    min_val=feature_column.min()
    if min_val<0:
        feature_column=feature_column+min_val*-1+1
    return chi2(feature_column,y)