LLM-SR

An LLM proposes equation shapes as Python functions, an optimizer fits their constants to data, and the scores steer later proposals.

Read the paper

The loop

  1. Proposes

    Equation skeletons as Python functions with placeholder parameters

  2. Judged by

    Fitting parameters with BFGS or Adam and scoring negative mean squared error against data

  3. Steers

    An experience buffer of 10 islands feeds the best equations (k=2) into the next prompt

Headline result

Across four problems (two oscillators, E. coli growth, aluminum stress-strain) with about 2.5K iterations, LLM-SR beat symbolic regression baselines on normalized MSE, most clearly out of domain: for E. coli growth 0.0037 against 1.0141 for the best baseline.

What this does not prove

Four benchmarks, two of them custom-built. Baselines (e.g. PySR) ran with far more evaluations (2M+). Results use GPT-3.5-turbo or Mixtral-8x7B; the best model differs by problem.

How it generalizes the harness

The island-based search with data fitting is the solver, and the discovered equation is a compact scientific artifact usable without the LLM.

Classification

Classification of LLM-SR
What it proposesEquation
Generative modelFrozen LLM (GPT-3.5-turbo, Mixtral-8x7B)
Algorithmic authorityNumerical fit to data scored by error
FeedbackScore
What gets updatedPrompt context and population of candidates
When it runsAt inference time
ValidityEmpirical (measured)
EvidenceExperiments reported
LineageDerivative