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

# Dask

> Run StatsForecast distributedly on top of Dask.

StatsForecast works on top of Spark, Dask, and Ray through
[Fugue](https://github.com/fugue-project/fugue/). StatsForecast will
read the input DataFrame and use the corresponding engine. For example,
if the input is a Spark DataFrame, StatsForecast will use the existing
Spark session to run the forecast.

## Installation

As long as Dask is installed and configured, StatsForecast will be able
to use it. If executing on a distributed Dask cluster, make use the
`statsforecast` library is installed across all the workers.

## StatsForecast on Pandas

Before running on Dask, it’s recommended to test on a smaller Pandas
dataset to make sure everything is working. This example also helps show
the small differences when using Dask.

```python theme={null}
from statsforecast.core import StatsForecast
from statsforecast.models import ( 
    AutoARIMA,
    AutoETS,
)
from statsforecast.utils import generate_series
```

```python theme={null}
n_series = 4
horizon = 7

series = generate_series(n_series)

sf = StatsForecast(
    models=[AutoETS(season_length=7)],
    freq='D',
)
sf.forecast(df=series, h=horizon).head()
```

|   | unique\_id | ds         | AutoETS  |
| - | ---------- | ---------- | -------- |
| 0 | 0          | 2000-08-10 | 5.261609 |
| 1 | 0          | 2000-08-11 | 6.196357 |
| 2 | 0          | 2000-08-12 | 0.282309 |
| 3 | 0          | 2000-08-13 | 1.264195 |
| 4 | 0          | 2000-08-14 | 2.262453 |

## Executing on Dask

To run the forecasts distributed on Dask, just pass in a Dask DataFrame
instead.

```python theme={null}
import dask.dataframe as dd
```

```python theme={null}
series['unique_id'] = series['unique_id'].astype(str)
ddf = dd.from_pandas(series, npartitions=4)
sf.forecast(df=ddf, h=horizon).compute().head()
```

|   | unique\_id | ds                  | AutoETS  |
| - | ---------- | ------------------- | -------- |
| 0 | 0          | 2000-08-10 00:00:00 | 5.261609 |
| 1 | 0          | 2000-08-11 00:00:00 | 6.196357 |
| 2 | 0          | 2000-08-12 00:00:00 | 0.282309 |
| 3 | 0          | 2000-08-13 00:00:00 | 1.264195 |
| 4 | 0          | 2000-08-14 00:00:00 | 2.262453 |