> For the complete documentation index, see [llms.txt](https://archivedocs.stackstate.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://archivedocs.stackstate.com/5.1/develop/reference/scripting/script-apis/prediction.md).

# Prediction - script API

## Function: `Prediction.predictMetrics(predictorName: String, horizon: Duration, query: String)`

Predict metrics for any metric query coming from any data source.

### Args

* `predictorName` - the prediction preset to use:
  * **fft** - Fast Fourier Transformation. Used for seasonal metrics with a repeatable pattern that has a cycle.
  * **linear** - Used for metrics that have a linear trend.
  * **hmn** - Harmonic Mean Normal. Used in difficult cases when metrics aren't clearly seasonal or linear.
* `horizon` - How much future to predict. The horizon is specified in [duration format](/5.1/develop/reference/scripting/time-in-scripts.md).
* `query` - The metrics to use for the prediction. A telemetry query that returns metrics, created using the `Telemetry.query()` function followed by `.compileQuery()`.

### Builder methods

* `predictionPoints(points: Int)` - the number of points to the horizon.
* `includeHistory(start?: Instant, end?: Instant)` - call this builder method to include the result of the `query` in the return value. Optionally a start and end can be added to limit the included history using the [instant format](/5.1/develop/reference/scripting/script-apis/time.md). When not specifying the start and end the whole history will be included.

### Return type

`AsyncScriptResult[PredictionResponse]`

A `PredictionResponse`, which has the following fields:

Fields:

* `PredictionResponse.request` - the request made to the prediction API of type `PredictionRequest`.
* `PredictionResponse.history` - optional, the history used for prediction of type `MetricTelemetry`. Empty if `.includeHistory()` was not used.
* `PredictionResponse.prediction` - the predicted metrics.

The `PredictionRequest` type has the following fields:

* `PredictionRequest.query` - the query provided to `predictMetrics`.
* `PredictionRequest.predictor` - the name and configuration of the predictor.
* `PredictionRequest.horizon` - the prediction horizon.
* `PredictionRequest.predictionPointCount` - the number of predicted points.
* `PredictionRequest.historyResponse` - options of the history response.

The `MetricTelemetry` has the following fields:

* `MetricTelemetry.result.data` - the two-dimensional array with values and time stamps.

### Examples

Predict 8 points of disk utilization for `myHost` for the next four hours based on the last four weeks of data:

```
Prediction.predictMetrics("linear", "4h",
    Telemetry.query("MyDatasource", 'host="myHost" and name="diskutil"')
        .metricField("value")
        .start("-4w")
        .compileQuery()
).includeHistory().predictionPoints(8)
```