Tweedie distribution
The Tweedie distribution is a family of exponential-dispersion probability distributions that includes compound Poisson-gamma and related discrete or continuous cases.
Ensemble Methods for Machine Learning
A Tweedie distribution is a family of exponential-dispersion distributions that, for 1<p<2, represents compound Poisson-gamma behavior with a mass at zero and positive continuous values.
- How it is used
- Models targets with a spike at zero and a right-skewed positive tail through a compound-distribution likelihood.
- How deep it goes
- Defines the power-family mapping and applies 1<p<2 through tuned GLM regression, without deriving the likelihood.
- Examples
- Uses rainfall and casual bike-user counts, inspecting zero spikes, right tails, log-transformed targets, and regression metrics.
- What you can do after
- Apply it via scikit-learn’s TweedieRegressor by tuning power and L2 regularization with cross-validation.
Read how Ensemble Methods for Machine Learning explains Tweedie distribution →
Machine Learning System Design
A family of exponential-dispersion probability distributions that includes several continuous, discrete, and compound Poisson-gamma cases.
- How it is used
- Frames Tweedie loss as a second-line experiment for predictive models involving count data.
- How deep it goes
- Defines the family through its distributional members and zero-continuous behavior without deriving its mathematics.
- Examples
- Uses normal, gamma, inverse Gaussian, scaled Poisson, and compound Poisson–gamma distributions as family cases.
Read how Machine Learning System Design explains Tweedie distribution →
Related concepts
- TweedieRegressorused by · TweedieRegressor is a scikit-learn estimator that fits generalized linear regression models with a Tweedie distribution and configurable power parameter.
- LightGBMused by · LightGBM is an open-source gradient-boosting framework for efficiently training tree-based machine-learning models.
- Poisson-gamma distributionuses · A Poisson-gamma distribution is a hybrid distribution combining a Poisson component for a point mass at zero with a gamma component for positive continuous values.
- count dataaddresses · Count data consist of nonnegative integer-valued observations representing numbers of events, items, or occurrences.
- Poisson distributionhas part · The Poisson distribution is a discrete probability distribution that models the count of events occurring independently at a constant average rate within a fixed interval or exposure.
- gamma distributionhas part · The gamma distribution is a continuous probability distribution over positive values, characterized by shape and scale or rate parameters.
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