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# DetectTrajectoriesRequest

A request that detects the trajectories of shapes moving along a parabolic path.

```
final class DetectTrajectoriesRequest
```

## Overview

After the request detects a trajectory, it produces a collection of [`TrajectoryObservation`](/documentation/Vision/TrajectoryObservation) objects that contain the shape’s detected points and an equation describing the parabola.

## Topics

### Creating a request

[`init(trajectoryLength:_:frameAnalysisSpacing:)`](/documentation/Vision/DetectTrajectoriesRequest/init(trajectoryLength:_:frameAnalysisSpacing:))

Creates a trajectory-detection request.

### Performing a request

[`perform(on:orientation:)`](/documentation/Vision/ImageProcessingRequest/perform(on:orientation:)-80bya)

Performs the request on an image URL and produces observations.

[`perform(on:orientation:)`](/documentation/Vision/ImageProcessingRequest/perform(on:orientation:)-3f3f1)

Performs the request on image data and produces observations.

[`perform(on:orientation:)`](/documentation/Vision/ImageProcessingRequest/perform(on:orientation:)-qxxx)

Performs the request on a Core Graphics image and produces observations.

[`perform(on:orientation:)`](/documentation/Vision/ImageProcessingRequest/perform(on:orientation:)-xspx)

Performs the request on a pixel buffer and produces observations.

[`perform(on:orientation:)`](/documentation/Vision/ImageProcessingRequest/perform(on:orientation:)-3hddl)

Performs the request on a Core Media buffer and produces observations.

[`perform(on:orientation:)`](/documentation/Vision/ImageProcessingRequest/perform(on:orientation:)-85ex1)

Performs the request on a Core Image image and produces observations.

### Understanding the result

[`TrajectoryObservation`](/documentation/Vision/TrajectoryObservation)

An observation that describes a detected trajectory.

### Configuring a request

[`objectMaximumNormalizedRadius`](/documentation/Vision/DetectTrajectoriesRequest/objectMaximumNormalizedRadius)

The maximum radius of the bounding circle of the object to track.

[`objectMinimumNormalizedRadius`](/documentation/Vision/DetectTrajectoriesRequest/objectMinimumNormalizedRadius)

The minimum radius of the bounding circle of the object to track.

[`targetFrameTime`](/documentation/Vision/DetectTrajectoriesRequest/targetFrameTime)

The requested target frame time for processing trajectory detection.

[`trajectoryLength`](/documentation/Vision/DetectTrajectoriesRequest/trajectoryLength)

The number of points to detect before calculating a trajectory.

### Getting the revision

[`revision`](/documentation/Vision/DetectTrajectoriesRequest/revision-swift.property)

The algorithm or implementation the request uses.

[`supportedRevisions`](/documentation/Vision/DetectTrajectoriesRequest/supportedRevisions)

The collection of revisions the request supports.

[`Revision`](/documentation/Vision/DetectTrajectoriesRequest/Revision-swift.enum)

A type that describes the algorithm or implementation that the request performs.

## Relationships

### Conforms To

[`Equatable`](/documentation/Swift/Equatable)

[`VisionRequest`](/documentation/Vision/VisionRequest)

[`ImageProcessingRequest`](/documentation/Vision/ImageProcessingRequest)

[`StatefulRequest`](/documentation/Vision/StatefulRequest)

[`SendableMetatype`](/documentation/Swift/SendableMetatype)

[`CustomStringConvertible`](/documentation/Swift/CustomStringConvertible)

[`Hashable`](/documentation/Swift/Hashable)

[`Sendable`](/documentation/Swift/Sendable)

---

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