# ST_XMAX

The ST_XMAX function extracts the maximum value of the x coordinates from the supplied geometry.

## Syntax

`ST_XMAX(point)`

### Parameters

#### point

This is an expression of type `geo_point`, `geo_shape`, `cartesian_point` or `cartesian_shape`. The function returns `null` if the point is `null`.

## Examples

Here's an example of how to use the ST_XMAX function:

```esql
FROM airport_city_boundaries
| WHERE abbrev == "CPH"
| EVAL envelope = ST_ENVELOPE(city_boundary)
| EVAL xmin = ST_XMIN(envelope), xmax = ST_XMAX(envelope), ymin = ST_YMIN(envelope), ymax = ST_YMAX(envelope)
| KEEP abbrev, airport, xmin, xmax, ymin, ymax
```

In this example, the ST_XMAX function is used to extract the maximum x coordinate from the envelope of the 'city_boundary' field.
