# findCubicLaneBoundaries

Find boundaries using cubic model

## Syntax

## Description

uses the random sample consensus (RANSAC) algorithm to find cubic lane boundary
models that fit a set of boundary points and an approximate width. Each model in
the returned array of `boundaries`

= findCubicLaneBoundaries(`xyBoundaryPoints`

,`approxBoundaryWidth`

)`cubicLaneBoundary`

objects contains the ```
[A B C
D]
```

coefficients of its third-degree polynomial equation and the
strength of the boundary estimate.

`[`

also returns a cell array of inlier boundary points for each boundary model
found, using the previous input arguments.`boundaries`

,`boundaryPoints`

]
= findCubicLaneBoundaries(`xyBoundaryPoints`

,`approxBoundaryWidth`

)

`[___] = findCubicLaneBoundaries(___,`

uses options specified by one or more `Name,Value`

)`Name,Value`

pair
arguments, with any of the preceding syntaxes.

## Examples

## Input Arguments

## Output Arguments

## Tips

To fit a single boundary model to a double lane marker, set the

`approxBoundaryWidth`

argument to be large enough to include the width spanning both lane markers.

## Algorithms

This function uses

`fitPolynomialRANSAC`

to find cubic models. Because this algorithm uses random sampling, the output can vary between runs.The

`maxDistance`

parameter of`fitPolynomialRANSAC`

is set to half the width specified in the`approxBoundaryWidth`

argument. Points are considered inliers if they are within the boundary width. The function obtains the final boundary model using a least-squares fit on the inlier points.

## Extended Capabilities

## Version History

**Introduced in R2018a**

## See Also

`cubicLaneBoundary`

| `birdsEyeView`

| `monoCamera`

| `segmentLaneMarkerRidge`

| `fitPolynomialRANSAC`

| `birdsEyePlot`