stan-dev / stan-dev/math

Support "individual"-specific intercept `alpha` in categorical_logit_glm

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Dominant language
C++
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Forks
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Avg merge
2d 4h
Merged PRs (30d)
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Description

The newish categorical_logit_glm function is a great improvement over "manual" softmax regression in terms of efficiency, but I noticed that the current signatures do not allow a case where each "individual" has their own intercept term alpha, i.e. it is an NxM matrix (where N is the number of categories and M is the number of individuals). This is supported in other glm versions such as bernoulli_logit_glm.

Current Version:

v4.3.2

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Research direction

Start by locating the categorical_logit_glm signatures and compare them with the bernoulli_logit_glm versions that support individual-specific intercepts. Trace the existing categorical_logit_glm implementation and its tests to determine the required NxM alpha behavior. Done means categorical_logit_glm supports an individual-specific alpha matrix consistently with the requested case.

Written by the indexing model from the issue text.

Assessment

Tech stack
cpp
Domain
machine-learning
Issue type
Feature
Difficulty
4/5
Estimated time
3-5 days
Activity status
Stale
Clarity
Mostly clear
Newbie friendliness
35/100

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