> ## Documentation Index
> Fetch the complete documentation index at: https://offthepace.mintlify.site/llms.txt
> Use this file to discover all available pages before exploring further.

# int_cell_power_law_fit

> WI-17: the pooled fit and training target, one per race x compound hardness rank.

<Note>Part of the [Physics](/transform/families/physics) family.</Note>

WI-17: the pooled fit and training target, one per race x compound hardness rank. Each stint keeps its own intercept; within-stint demeaning removes it, beta is profiled on the grid and alpha is OLS through the origin. curve\_incr\_\{5,10,15,20}\_s is the curve over the fresh-tyre pace at tyre age 2 (the simulator's anchor), the quantity Step 0 found identified (reliability ceiling 0.58-0.76) where alpha is not (0.07). fit\_eligible: >= 3 qualifying stints (>= 5 laps over >= 2 ages) and >= 40 laps. No 2025 cells (no rank).

## Lineage

```mermaid theme={null}
flowchart LR
  int_power_law_lap --> int_cell_power_law_fit
  int_cell_power_law_fit --> fct_power_law_training
  style int_cell_power_law_fit fill:#e40404,stroke:#e40404,color:#fff
```

## Overview

| Property | Value |
| - | - |
| Layer | `intermediate` |
| Family | [Physics](/transform/families/physics) |
| Contract enforced | No |
| Upstream | [`int_power_law_lap`](./int_power_law_lap) |
| Model-level tests | `unique_combination_of_columns` |

**10 tests** [guard](/transform/ci/overview) this model  -  8 generic, 2 singular.

## Columns

| Column | Type | Nullable | Tests | Description |
| - | - | - | - | - |
| `cell_id` | | Yes | [`not_null`](/transform/ci/structural), [`unique`](/transform/ci/structural) | |
| `compound_hardness_rank` | | Yes | [`not_null`](/transform/ci/structural) | |
| `n_compound_labels` | | Yes | [`accepted_values`](/transform/ci/range-and-domain) | Distinct compound names in the cell; 1 by construction (one C-code per label per race). |
| `beta` | | Yes | [`not_null`](/transform/ci/structural) | |
| `r2_within` | | Yes | [`not_null`](/transform/ci/structural) | |
| `fit_eligible` | | Yes | [`not_null`](/transform/ci/structural) | |


This documentation is built and hosted on [Mintlify](https://mintlify.com), a developer documentation platform.