RegressionSample

Ridge & lasso regression

A flexible polynomial kept in check by a penalty on large coefficients.

Synthetic data, generated and trained in your browser.

Try this

  1. 01Start at the smallest λ: the coefficient bars hit their caps and the curve wiggles.
  2. 02Switch to lasso and raise λ: watch coefficients drop to zero one by one.
  3. 03Push λ to 1: both penalties flatten the curve towards the mean.

How it works

  1. 1Start from a degree-10 polynomial that would normally overfit.
  2. 2Add a penalty to the loss: the sum of squared coefficients (ridge) or of their absolute values (lasso).
  3. 3λ sets the trade-off between fitting the data and keeping coefficients small.
  4. 4Lasso can set coefficients exactly to zero, selecting features; ridge only shrinks them.

What the controls teach

Penalty
Ridge shrinks every coefficient smoothly; lasso pushes the least useful ones to exactly zero.
Regularization λ
Penalty strength. Near zero it overfits like plain polynomial regression; large values flatten the curve.

Use it when

  • Many correlated or noisy features
  • You want a simpler model (lasso)

Avoid it when

  • Features on different scales without standardising them first

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