---
url: >-
  https://jer-k.github.io/effect-prophet/benchmarks/linear/map-explicit-break-small.md
---

# One hand-picked changepoint

 [← All linear growth benchmarks](/benchmarks/linear)

32 daily rows with a changepoint on 13 January and a looser prior scale of 0.2.

## Input

[`benchmark/inputs/v1/linear-small.json`](https://github.com/jer-k/effect-prophet/blob/main/benchmark/inputs/v1/linear-small.json): 32 history rows and 16 forecast rows.

## Output

Largest difference: **1.0e-11** (< 0.0001% of the input's range).

Every forecast row from both libraries.

| Date | Effect Prophet | Python Prophet | Difference |
| --- | ---: | ---: | ---: |
| 2020-02-02 | 23.3806 | 23.3806 | 1.0e-11 |
| 2020-02-03 | 23.7230 | 23.7230 | 1.0e-11 |
| 2020-02-04 | 24.0653 | 24.0653 | 1.0e-11 |
| 2020-02-05 | 24.4076 | 24.4076 | 1.0e-11 |
| 2020-02-06 | 24.7500 | 24.7500 | 1.0e-11 |
| 2020-02-07 | 25.0923 | 25.0923 | 1.0e-11 |
| 2020-02-08 | 25.4346 | 25.4346 | 1.0e-11 |
| 2020-02-09 | 25.7769 | 25.7769 | 1.0e-11 |
| 2020-02-10 | 26.1193 | 26.1193 | 1.0e-11 |
| 2020-02-11 | 26.4616 | 26.4616 | 9.9e-12 |
| 2020-02-12 | 26.8039 | 26.8039 | 9.9e-12 |
| 2020-02-13 | 27.1463 | 27.1463 | 9.9e-12 |
| 2020-02-14 | 27.4886 | 27.4886 | 9.9e-12 |
| 2020-02-15 | 27.8309 | 27.8309 | 9.8e-12 |
| 2020-02-16 | 28.1733 | 28.1733 | 9.8e-12 |
| 2020-02-17 | 28.5156 | 28.5156 | 9.8e-12 |

## Timing

Median of all measured repetitions.

| Step | Effect Prophet | Python Prophet | Effect Prophet is |
| --- | ---: | ---: | --- |
| Convert input rows | 6 µs | 451 µs | 78× faster |
| Fit | 1.89 ms | 11.0 ms | 5.8× faster |
| Predict | 229 µs | 2.75 ms | 12× faster |
| Fit and predict | 2.11 ms | 13.8 ms | 6.5× faster |
| Convert, fit and predict | 1.78 ms | 14.1 ms | 7.9× faster |
| First forecast in a new process | 184 ms | 1.45 s | 7.9× faster |
| Save model to JSON | 23 µs | 359 µs | 16× faster |
| Load model from JSON | 106 µs | 1.97 ms | 18× faster |
| Load and predict in a new process | 163 ms | 1.42 s | 8.7× faster |

## Settings

The case declaration both libraries ran.

```json
{
  "kind": "linear-map",
  "comparison": {
    "kind": "equivalent-objective",
    "evidenceId": "linear-output-first-v4"
  },
  "configuration": {
    "effectMap": "explicit",
    "changepoints": {
      "mode": "explicit",
      "timestamps": [
        "2020-01-13T00:00:00.000Z"
      ]
    },
    "changepointPriorScale": 0.2,
    "seasonalities": [],
    "events": [],
    "regressors": []
  },
  "effectOptimizer": {
    "algorithm": "auto",
    "maxIterations": 10000,
    "fallback": "newton",
    "lbfgs": {
      "historySize": 5,
      "initAlpha": 0.001,
      "tolObj": 1e-12,
      "tolRelObj": 10000,
      "tolGrad": 1e-8,
      "tolRelGrad": 10000000,
      "tolParam": 1e-8
    }
  },
  "pythonOptimizer": {
    "algorithm": "Auto",
    "maxIterations": 10000,
    "newtonFallback": true,
    "sigFigs": 12
  }
}
```