Truncated Poisson graphical model
Model Families AIMech:TruncatedPoissonGraphicalModel DRAFT
Aliases: TPGM, Truncated Poisson Markov random field
A finite pairwise count graphical model with a fixed upper count limit, factorial base measures and Poisson-kernel full conditionals renormalized over the bounded support, allowing finite symmetric interactions of either sign.
Identity Notes & Concept Scope
The TPGM in Yang et al. conditions a Poisson kernel on counts no larger than R. It does not Winsorize by moving all tail mass to the cutoff. The cutoff belongs to the model support, not merely an observation-clipping procedure. TPGM is distinct from the classical unbounded auto-Poisson field and from an auto-binomial field with combinatorial trial-count factors. Its full conditionals are truncated Poisson laws; this does not assert the same family for every marginal distribution. No normalized identity match was found across all 442 pinned AIO labels and all scoped synonyms and 406 preceding native IDs, names and aliases. Fixed-string full-checkout searches included ignored and hidden files in worktree and main, yielding six and six matched lines; all five unique contents were read. Hits are the prior publication lead and source URLs, not existing records of these identities. All 185 semantic label/synonym hits were read. Forty-five fully annotated exact CLASS nodes and outgoing edges were inspected: 43 byte-equivalent to prior inspected nodes and two freshly read. Fifty-nine contextual YAMLs comprise 45 generated and 14 native records: 54 byte-verified after prior reading and five freshly read. Acronyms were included in normalized identity comparison and the text-search terms. Absence is bounded to the pinned snapshot, maintained corpus and inspected semantic neighborhood.
Claims & Grounded Evidence
1 Claim
Mechanism
#method
For a finite graph with X_i in {0,...,R} and fixed integer R>=1, define p(x)=Z^(-1)*exp[sum_i(a_i*x_i-log(x_i!))+sum_(i<j) b_ij*x_i*x_j], using symmetric b_ij and zero coefficients on nonedges. Finite real parameters give a finite positive Z on the finite support. The full conditional at i is proportional to exp(eta_i*k)/k! for k=0,...,R, where eta_i=a_i+sum_(j!=i) b_ij*x_j. Its normalizer is C_R(lambda_i)=sum_(k=0)^R lambda_i^k/k!, with lambda_i=exp(eta_i). Thus lambda_i is the underlying Poisson parameter, while the actual truncated conditional mean is lambda_i*C_(R-1)(lambda_i)/C_R(lambda_i). This mean is generally not lambda_i. With all edge parameters zero the joint factors into independent truncated Poisson laws.
⚠️ Curated Limitations & Negative Results
- Positive interactions and large neighboring counts can concentrate conditional mass at the cutoff. R changes the model, and a cutoff selected as the observed maximum does not guarantee that future counts will lie within its support.
- The unbounded limit cannot retain arbitrary positive pairwise coefficients while preserving the classical Poisson joint law. Finite-support normalizability is not evidence of unbounded-model validity.
- The source Theorem 1 is worded as a universal impossibility result for Winsorized conditionals, but independent constant-parameter Winsorized variables form a valid joint product. Its supplemental contradiction assumes nonzero interaction. Original calculations preserve that exception and separately show incompatibility of one symmetric log-mean interacting specification; the blanket impossibility statement is not adopted.
- The finite graph and the symmetric once-counted edge parameters must be specified. Independently fitted node regressions do not automatically agree on a compatible joint parameterization. Model definition, numerical estimation and graph selection are distinct.
- The source sketches l1-penalized neighborhood fitting, but explicitly leaves extensions of statistical graph-recovery guarantees to future work. A model existence result is not a sparsistency theorem or a guarantee that a chosen approximate optimizer finds the intended fit.
- The reported network experiments are contextual evidence, not a universal performance guarantee. The processed breast-cancer microRNA data and cited biological associations do not establish causal regulation or clinical predictive validity. No author implementation, empirical fit or benchmark was reproduced.
Artificial Intelligence Ontology (AIO) Grounding
Mapped AIO Classes
| AIO Target Class | Mapping Relation | Mapping Rationale |
|---|---|---|
AIO:Model
Model
|
broad_match | This is a specified joint probability family on integer-valued graph sites and falls within the broader mathematical representation described by Model. A particular optimizer or prediction task is not its identity. |
AIO:ProbabilisticGraphicalModel
Probabilistic Graphical Model
|
related_match | The family encodes undirected graphical conditional dependencies. The pinned target is task-scoped, so a related mapping connects this probability model to graphical modeling without asserting a model is-a task relationship. |
Evidence Sources & Primary Literature
2 Sources| Source ID | Publication / Document | Type / Access | Reference & Checksum |
|---|---|---|---|
method-source
|
Eunho Yang, Pradeep Ravikumar, Genevera I. Allen, Zhandong Liu
|
primary paper
full_text
|
sha256:43358362c5a5…
|
supplement
|
Eunho Yang, Pradeep Ravikumar, Genevera I. Allen, Zhandong Liu
|
primary paper
full_text
|
sha256:38b42f678bb1…
|
Curation Provenance
Curator: Codex
Method: ai_assisted
Model: GPT-6
Created: 2026-10-11T22:28:17Z
Updated: 2026-10-11T22:28:17Z
Source File:
data/curated/TruncatedPoissonGraphicalModel.yaml