its
Apply segmented regression to interrupted time series data, estimating changes in level and trend after an intervention, with validated evidence tier for causal decision support.
Instructions
Segmented regression for interrupted time series. Validation: validated evidence tier (known-truth, reference, external-parity, or Monte Carlo artifact).
Input Schema
| Name | Required | Description | Default |
|---|---|---|---|
| y | Yes | Outcome column. | |
| time | No | Time column. If None, uses row index 0..n-1. | |
| alpha | No | Significance level for confidence intervals and tests. | |
| 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 |
| hac_lag | No | Newey-West truncation lag. | |
| 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 | Yes | 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. | |
| intervention | No | Time index (integer row position) at which the intervention begins. Required. | |
| data_sample_n | No | Optional uniform random subsample size (seed=0, deterministic) — useful on huge panels. | |
| seasonality_period | No | Period P of Fourier seasonal terms (e.g. 12 for monthly data with annual cycle). If None, no seasonality is added. | |
| seasonality_harmonics | No | seasonality_harmonics parameter (int). |
Output Schema
| Name | Required | Description | Default |
|---|---|---|---|
No arguments | |||