CogMath.DistancePointEllipse Method

CogMath DistancePointEllipse Method

Cognex VisionPro 9.21 SR1

Returns the shortest distance from the given point to the given ellipse. Also provides the closest point on the ellipse.

Namespace: Cognex.VisionPro
Assembly: Cognex.VisionPro.Core (in Cognex.VisionPro.Core.dll) Version: 85.1.0.0

Syntax

C++

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public static double DistancePointEllipse(
	double x,
	double y,
	CogEllipse ellipse,
	ICogImage image,
	out double ellipseX,
	out double ellipseY
)

public static double DistancePointEllipse(
	double x,
	double y,
	CogEllipse ellipse,
	ICogImage image,
	out double ellipseX,
	out double ellipseY
)

Public Shared Function DistancePointEllipse ( 
	x As Double,
	y As Double,
	ellipse As CogEllipse,
	image As ICogImage,
	<OutAttribute> ByRef ellipseX As Double,
	<OutAttribute> ByRef ellipseY As Double
) As Double

Public Shared Function DistancePointEllipse ( 
	x As Double,
	y As Double,
	ellipse As CogEllipse,
	image As ICogImage,
	<OutAttribute> ByRef ellipseX As Double,
	<OutAttribute> ByRef ellipseY As Double
) As Double

public:
static double DistancePointEllipse(
	double x, 
	double y, 
	CogEllipse^ ellipse, 
	ICogImage^ image, 
	[OutAttribute] double% ellipseX, 
	[OutAttribute] double% ellipseY
)

public:
static double DistancePointEllipse(
	double x, 
	double y, 
	CogEllipse^ ellipse, 
	ICogImage^ image, 
	[OutAttribute] double% ellipseX, 
	[OutAttribute] double% ellipseY
)

Parameters

x: Type: System Double
The x-coordinate of the point.

y: Type: System Double
The y-coordinate of the point.

ellipse: Type: Cognex.VisionPro CogEllipse
The ellipse.

image: Type: Cognex.VisionPro ICogImage
An image that specifies the coordinate space to use.

ellipseX: Type: System Double
The x-coordinate of the nearest point on the ellipse. If the point is on the ellipse, this value is the same as x. If the ellipse is a circle and (x,y) is the center of the circle, this value is the x-coordinate of an arbitrary point on the circle.

ellipseY: Type: System Double
The x-coordinate of the another point on the ellipse that is equidistant to (x,y).

Return Value

Type: Double

The shortest distance from the point (x,y) to the ellipse. If the point is inside the ellipse, the distance is negative.

Exceptions

Exception	Condition
ArgumentException	ellipse is NULL.
CogSpaceTreeInvalidNameSyntaxException	At least one shape's selected space names is not a legal space name.
CogSpaceTreeNotUniqueException	At least one shape's selected space names is a nonqualified space name and more than one instance of it exists in image's coordinate space tree.
CogSpaceTreeNotInTreeException	At least one shape does not exist in image's coordinate space tree.
CogImageNoTreeException	The coordinate space tree is missing from image.

Remarks

Returns the shortest distance from the given point to the given ellipse.

The following table describes how the relationship between the point (x,y) and ellipse affects the out parameters.

ConditionDistance(ellipseX,ellipseY)

Point inside

The negative of the shortest distance between (x,y) and ellipse.

The nearest point on ellipse

Point inside

The negative of the shortest distance between (x,y) and ellipse.

One of the equidistant points on ellipse

Point outside

The shortest distance between (x,y) and ellipse.

The nearest point on ellipse

Point on ellipse

(x,y)

Ellipse is a circle, point in center

The radius of the circle.

An arbitrary point on the circle

If you supply a value for the image parameter, then ellipse is mapped to the selected space of image before the measurement is computed and the result is expressed in that space. x and y are presumed to be expressed in the selected space of image.

If you do not supply a value for image, then ellipse, x, and y are presumed to be in the same coordinate space.