eslint-plugin-math

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math/prefer-math-hypot ​

enforce the use of Math.hypot() instead of other hypotenuse calculations

  • ⚙️ This rule is included in "plugin:math/recommended".
  • 🔧 The --fix option on the command line can automatically fix some of the problems reported by this rule.
  • 💡 Some problems reported by this rule are manually fixable by editor suggestions.

📖 Rule Details ​

This rule aims to enforce the use of Math.hypot() instead of other hypotenuse calculations.

Math.hypot() provides several advantages over manual Pythagorean theorem calculations:

  • Overflow protection: Avoids intermediate overflow when dealing with large numbers
  • Underflow protection: Prevents precision loss with very small numbers
  • Numerical stability: Uses algorithms optimized for floating-point arithmetic
  • Clarity: Expresses the mathematical intent more clearly
  • Variable arguments: Supports any number of dimensions, not just 2D
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The Numerical Stability Problem ​

Manual calculations can suffer from overflow/underflow issues:

js
// These can overflow with large numbers
const large = 1e200;
Math.sqrt(large * large + large * large)  // Infinity (overflow)

// Math.hypot handles this correctly
Math.hypot(large, large)  // 1.4142135623730951e+200 (correct)

// Similarly for very small numbers (underflow)
const small = 1e-200;
Math.sqrt(small * small + small * small)  // 0 (underflow)
Math.hypot(small, small)  // 1.4142135623730951e-200 (correct)

🔧 Options ​

Nothing.

📚 Further reading ​

🚀 Version ​

This rule was introduced in eslint-plugin-math v0.6.0

🔍 Implementation ​