# `pygeos.measurement`¶

`pygeos.measurement.``area`(geometry, **kwargs)

Computes the area of a (multi)polygon.

Parameters

geometry : Geometry or array_like

Examples

```>>> area(Geometry("POLYGON((0 0, 0 10, 10 10, 10 0, 0 0))"))
100.0
>>> area(Geometry("MULTIPOLYGON (((0 0, 0 10, 10 10, 0 0)), ((0 0, 0 10, 10 10, 0 0)))"))
100.0
>>> area(Geometry("POLYGON EMPTY"))
0.0
>>> area(None)
nan
```
`pygeos.measurement.``bounds`(geometry, **kwargs)

Computes the bounds (extent) of a geometry.

For each geometry these 4 numbers are returned: min x, min y, max x, max y.

Parameters

geometry : Geometry or array_like

Examples

```>>> bounds(Geometry("POINT (2 3)")).tolist()
[2.0, 3.0, 2.0, 3.0]
>>> bounds(Geometry("LINESTRING (0 0, 0 2, 3 2)")).tolist()
[0.0, 0.0, 3.0, 2.0]
>>> bounds(Geometry("POLYGON EMPTY")).tolist()
[nan, nan, nan, nan]
>>> bounds(None).tolist()
[nan, nan, nan, nan]
```
`pygeos.measurement.``distance`(a, b, **kwargs)

Computes the Cartesian distance between two geometries.

Parameters

a, b : Geometry or array_like

Examples

```>>> point = Geometry("POINT (0 0)")
>>> distance(Geometry("POINT (10 0)"), point)
10.0
>>> distance(Geometry("LINESTRING (1 1, 1 -1)"), point)
1.0
>>> distance(Geometry("POLYGON ((3 0, 5 0, 5 5, 3 5, 3 0))"), point)
3.0
>>> distance(Geometry("POINT EMPTY"), point)
nan
>>> distance(None, point)
nan
```
`pygeos.measurement.``hausdorff_distance`(a, b, densify=None, **kwargs)

Compute the discrete Haussdorf distance between two geometries.

The Haussdorf distance is a measure of similarity: it is the greatest distance between any point in A and the closest point in B. The discrete distance is an approximation of this metric: only vertices are considered. The parameter ‘densify’ makes this approximation less coarse by splitting the line segments between vertices before computing the distance.

Parameters

a, b : Geometry or array_like

densify : float, array_like or None

The value of densify is required to be between 0 and 1.

Examples

```>>> line_1 = Geometry("LINESTRING (130 0, 0 0, 0 150)")
>>> line_2 = Geometry("LINESTRING (10 10, 10 150, 130 10)")
>>> hausdorff_distance(line_1, line_2)
14.14...
>>> hausdorff_distance(line_1, line_2, densify=0.5)
70.0
>>> hausdorff_distance(line_1, Geometry("LINESTRING EMPTY"))
nan
>>> hausdorff_distance(line_1, None)
nan
```
`pygeos.measurement.``length`(geometry, **kwargs)

Computes the length of a (multi)linestring or polygon perimeter.

Parameters

geometry : Geometry or array_like

Examples

```>>> length(Geometry("LINESTRING (0 0, 0 2, 3 2)"))
5.0
>>> length(Geometry("MULTILINESTRING ((0 0, 1 0), (0 0, 1 0))"))
2.0
>>> length(Geometry("POLYGON((0 0, 0 10, 10 10, 10 0, 0 0))"))
40.0
>>> length(Geometry("LINESTRING EMPTY"))
0.0
>>> length(None)
nan
```
`pygeos.measurement.``total_bounds`(geometry, **kwargs)

Computes the total bounds (extent) of the geometry.

Parameters

geometry : Geometry or array_like

Returns

numpy ndarray of [xmin, ymin, xmax, ymax]

```>>> total_bounds(Geometry("POINT (2 3)")).tolist()
```

[2.0, 3.0, 2.0, 3.0]

```>>> total_bounds([Geometry("POINT (2 3)"), Geometry("POINT (4 5)")]).tolist()
```

[2.0, 3.0, 4.0, 5.0]

```>>> total_bounds([Geometry("LINESTRING (0 1, 0 2, 3 2)"),Geometry("LINESTRING (4 4, 4 6, 6 7)")]).tolist()
```

[0.0, 1.0, 6.0, 7.0]

```>>> total_bounds(Geometry("POLYGON EMPTY")).tolist()
```

[nan, nan, nan, nan]

```>>> total_bounds([Geometry("POLYGON EMPTY"), Geometry("POINT (2 3)")]).tolist()
```

[2.0, 3.0, 2.0, 3.0]

```>>> total_bounds(None).tolist()
```

[nan, nan, nan, nan]