# Automatic reparametrizations of distributions in Distributions.jl
**URL:** https://discourse.julialang.org/t/automatic-reparametrizations-of-distributions-in-distributions-jl/132431
**Category:** Statistics
**Tags:** distributions
**Created:** [September 16, 2025, 9:11am UTC](https://discourse.julialang.org/t/automatic-reparametrizations-of-distributions-in-distributions-jl/132431 "2025-09-16T09:11:24Z")
**Posts on this page:** 3
**Page:** 1
### Author:  [@giovannitinervia9](https://discourse.julialang.org/u/giovannitinervia9)
#### Post date: [September 16, 2025, 9:11am UTC](https://discourse.julialang.org/t/automatic-reparametrizations-of-distributions-in-distributions-jl/132431/1 "2025-09-16T09:11:24Z")
Hi everyone,
I’m thinking about a potential feature for the **Distributions.jl** package that would be nice to have. Would it be possible to implement a function, let’s say `reparametrize`, that takes an existing distribution and a parameter transformation function to create a new distribution object?
For example, a common reparametrization is moving from the standard deviation to precision. We could define a transformation for a `Normal(μ, σ)` distribution to a new version parametrized by `τ = 1/σ²`.
This would streamline our workflow and reduce the need for writing custom distribution types for common transformations. It feels like a powerful tool for building flexible statistical models.
What do you all think? Is this concept feasible, and has anything like it been proposed or implemented before?
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### Author:  [@aplavin](https://discourse.julialang.org/u/aplavin)
#### Post date: [September 16, 2025, 12:24pm UTC](https://discourse.julialang.org/t/automatic-reparametrizations-of-distributions-in-distributions-jl/132431/2 "2025-09-16T12:24:40Z")
What interface do you need for these reparametrizations? Eg, would adding a `precision(d::Normal) = 1/σ^2` function would be enough?
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### Author:  [@seabbs](https://discourse.julialang.org/u/seabbs)
#### Post date: [August 6, 2026, 9:53am UTC](https://discourse.julialang.org/t/automatic-reparametrizations-of-distributions-in-distributions-jl/132431/3 "2026-08-06T09:53:24Z")
I also really wanted this and have implemented something like it here: [ReparameterisedDistributions.jl](https://reparameteriseddistributions.epiaware.org/dev/)