Christopher Csiszar
Data Science | Math | Finance | Business | Economics
Beware Default Random Forest Importances
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Unreliable Default Feature Importances: The default feature importance strategies in scikit-learn’s Python implementation and R’s Random Forest do not provide reliable results when predictor variables vary in scale or number of categories.
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Use Permutation Importance: To ensure accurate feature importance, use permutation importance. In Python, this can be done using the rfpimp package. In R, set importance=T in the Random Forest constructor and type=1 in the importance() function.
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Preferred Strategies for All Models: For all machine learning models, prefer permutation or drop-column importance strategies over interpreting internal model parameters as proxies for feature importances.
An Easy to Use Waterfall Chart Function for Python
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Effective Visualization Tool: Waterfall charts are excellent for visualizing marginal value contributions to a system or initial value, providing clear insights into changes over time.
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User-Friendly Python Package: This package offers a hassle-free way to generate waterfall charts in Python, enhancing data range reliability, appearance, and chart options.
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Versatile Applications: Waterfall charts can creatively display various data, from revenue and expenses to any system’s marginal contributions, making them universally applicable.
Internal Charles River Associates Presentation
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Setting Up for Web Scraping: Use an Integrated Development Environment (IDE) to ensure your web scraping projects are organized, repeatable, and efficient. Your IDE should have a source code editor, a project files directory, and a Python console.
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Basic Commands for Web Scraping: Learn essential Python commands for web scraping, such as pausing scripts, storing text from web elements, printing output, and creating or writing to files.
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Introduction to Web Scraping: Web scraping involves extracting unstructured data from websites and transforming it into structured data for analysis. Python, with its rich library ecosystem, is highly recommended for web scraping projects.