survreg
Fit parametric accelerated failure time survival models to time-to-event data, producing coefficients, diagnostics, and confidence intervals for evidence-backed rollout or hold decisions.
Instructions
Parametric survival model (AFT parameterization). Validation: certified parity evidence.
Input Schema
| Name | Required | Description | Default |
|---|---|---|---|
| x | No | Covariate columns (or formula RHS). | |
| dist | No | dist parameter (str). | weibull |
| alpha | No | Significance level for confidence intervals and tests. | |
| event | No | Event indicator column. | |
| detail | No | Payload depth: 'minimal' (~150 tokens) for sub-step calls where only the point estimate is needed; 'standard' (~1K tokens) for diagnostics + coefficient table; 'agent' (~2K tokens, default) adds violations / next_steps / suggested_functions so the LLM can plan its next call without another round-trip. | agent |
| robust | No | Robust standard-error or covariance estimator option. | nonrobust |
| cluster | No | Cluster identifier column for clustered standard errors. | |
| formula | No | Formula ``'duration ~ x1 + x2'``. | |
| duration | No | Follow-up time column (or formula LHS). | |
| as_handle | No | If true, cache the fitted result on the server and return result_id + result_uri alongside the JSON payload so a subsequent tools/call can chain without re-running. | |
| data_path | No | Absolute path or URL to a data file. Supported: .csv / .tsv / .txt (delimited), .parquet / .pq, .feather / .arrow, .xlsx / .xls, .dta (Stata), .json / .jsonl. Schemes: file://, s3://, gs://, https://. | |
| result_id | No | Optional handle to a previously-fitted result (returned by an earlier call when as_handle=true). Tools that operate on a fitted object accept this in place of re-supplying data_path + columns. | |
| data_columns | No | Optional column projection. Parquet/Feather/Stata loaders honour this for fast partial reads. | |
| data_sample_n | No | Optional uniform random subsample size (seed=0, deterministic) — useful on huge panels. |
Output Schema
| Name | Required | Description | Default |
|---|---|---|---|
No arguments | |||