异常检测
使用Z分数和TQR检测异常
使用Z分数
i> finding mean and standard deviation of the dataset
ii> finding Z score, Z = (X-u)/sigma
iii> values for which Z > Threshold are outliers
使用IQR:-
i> interquantile range works on percentile
ii> sort the data in increasing order
iii> let 25 and 75 percentile values be x and y respectively
iv> finding IQR = y-x
ii> values not in the range (x-1.5*IQR,y+1.5*I