outlier-detective

Detect anomalies in numerical datasets using IQR, Z-score, Isolation Forest, and LOF.

86|18|Updated Dec 14, 2025
One-click install
npx skills add https://github.com/dkyazzentwatwa/chatgpt-skills --skill outlier-detective
Or copy as Structured Prompt for Agent
Please help me install this Agent Skill.
Skill: outlier-detective
Source: https://github.com/dkyazzentwatwa/chatgpt-skills/tree/main/outlier-detective
Command: npx skills add https://github.com/dkyazzentwatwa/chatgpt-skills --skill outlier-detective

SYSTEM DOCUMENTATION & REQUIREMENTS

💡 This Skill requires pandas, numpy, scipy, scikit-learn, matplotlib, and includes scripts (resource) and references (resource) components.

What problem does it solve?

This Skill helps identify and manage unusual or anomalous data points within datasets, which is crucial for data quality, fraud detection, and accurate analysis.

Core Features & Use Cases

  • Statistical Methods: Detect outliers using Z-score, IQR, and Modified Z-score.
  • ML Methods: Employ Isolation Forest and LOF for more complex anomaly detection.
  • Visualization: Generate box plots and distribution plots to visually inspect outliers.
  • Use Case: Clean a sales dataset by removing or flagging transactions with unusually high or low values before performing trend analysis.

Quick Start

Use the outlier-detective skill to find outliers in the 'revenue' column of your 'sales_data.csv' file using the IQR method.

Frequently Asked Questions about outlier-detective

High-intent search queries and answers about installing and using this skill.

FAQPage Schema
How do I detect outliers in a numerical dataset using Python?

You can detect outliers using statistical methods like Z-score and IQR or machine learning algorithms like Isolation Forest and LOF to identify anomalous data points in numerical datasets. This skill applies these techniques directly to pandas dataframes for data cleaning and quality control.

What is the best way to clean a sales dataset by flagging unusually high transactions?

The best way to clean a sales dataset is to apply the IQR or Modified Z-score method to flag transactions with unusually high or low values. This isolates anomalous revenue records before you perform trend analysis or generate distribution plots.

When should I use Isolation Forest vs Z-score for anomaly detection?

Use Z-score or IQR for basic statistical anomaly detection on normally distributed numerical data, and use Isolation Forest or LOF for complex machine learning outlier detection. This skill supports both approaches to handle varying data quality and fraud detection needs.

Can I generate box plots to visually inspect data anomalies?

Yes, you can generate box plots and distribution plots to visually inspect data anomalies. This skill uses matplotlib to create visualizations that help you assess outliers and understand the distribution of your numerical data during quality control analysis.

Does this anomaly detection method work with pandas and scikit-learn?

Yes, this anomaly detection method works with pandas and scikit-learn, along with numpy, scipy, and matplotlib. It integrates these dependencies to run statistical and machine learning outlier detection algorithms on your numerical datasets.