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THE FEUTEX TOOLKIT

Zero-Inflated Poisson Count Model

Estimate zero frequency and overdispersion when a count process has structural zeros.

Probability workspace● Runs in your browser
01 Your input
02 Your result
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FormulaProbability Zero = pi+(1-pi)*exp(-rate); Mean = (1-pi)*rate; Variance = (1-pi)*rate*(1+pi*rate)
Sources and model references

Made for real tasks

  • Estimate zero frequency and overdispersion when a count process has structural zeros.
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Worked example

Inputs

Structural-zero fraction
0.2 probability
Poisson mean in active group
3 number

Expected results

Probability Zero
0.2398296547 probability
Mean
2.4 count
Variance
3.84 count²

Load the example in the workspace to reproduce these results. Display rounding does not change the underlying calculation.

How to use this tool

  1. Enter structural-zero fraction, poisson mean in active group.
  2. Use the displayed units and confirm the model assumptions.
  3. Calculate and compare the outputs against your input scenario.

Try this example

{
  "pi": 0.2,
  "rate": 3
}

Accuracy and scope

Structural-zero mixture probability and active-group mean must be estimated separately; does not fit observed data.

Is my data uploaded?

This tool runs locally in your browser. Input and output are not sent to a processing server. Copy or download your result before leaving the page.