the+1.5+Iqr+rule+for+outliers
时间: 2023-12-29 21:26:28 浏览: 111
pyculiarity+时序数据异常检测
The 1.5 IQR rule is a commonly used method for identifying outliers in a dataset. It involves calculating the interquartile range (IQR) and then defining a threshold for outliers based on this range.
Here is how the 1.5 IQR rule works:
1. Calculate the IQR: The IQR is the range between the 25th percentile (Q1) and the 75th percentile (Q3) of the dataset. It can be calculated as Q3 - Q1.
2. Define the lower and upper thresholds: The lower threshold is calculated as Q1 - 1.5 * IQR, and the upper threshold is calculated as Q3 + 1.5 * IQR.
3. Identify outliers: Any data point that falls below the lower threshold or above the upper threshold is considered an outlier.
Here is an example of how to apply the 1.5 IQR rule for outliers in Python:
```python
import pandas as pd
# Assuming you have a DataFrame called 'data' with a column called 'value'
Q1 = data['value'].quantile(0.25)
Q3 = data['value'].quantile(0.75)
QR = Q3 - Q1
lower_threshold = Q1 - 1.5 * IQR
upper_threshold = Q3 + 1.5 * IQR
outliers = data[(data['value'] < lower_threshold) | (data['value'] > upper_threshold)]
```
In this example, the 'value' column in the 'data' DataFrame is used to calculate the IQR and identify outliers based on the 1.5 IQR rule.
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