FC_CircleThroughThreePoints2D

FC_CircleThroughThreePoints2D - General Information

Overview

Type:	Function
Available as of:	V1.0.3.0
Versions:	Current version

Task

Calculates a circle in the 2-dimensional space which passes through three specified points.

Description

Three points which must not be located on a straight line are specified in the 2-dimensional space. This function calculates the center and radius of the circle which passes through these three points.

Interface

Input	Data type	Description
i_stPoint1	ST_Vector2D	Point 1 which the circle is to pass through
i_stPoint2	ST_Vector2D	Point 2 which the circle is to pass through
i_stPoint3	ST_Vector2D	Point 3 which the circle is to pass through

Output	Data type	Description
q_etDiag	GD.ET_Diag	General library-independent statement on the diagnostic. A value not equal to ET_Diag.Ok corresponds to an diagnostic message.
q_etDiagExt	ET_DiagExt	POU-specific output on the diagnostic. q_etDiag = ET_Diag.Ok -> Status message q_etDiag <> ET_Diag.Ok -> Diagnostic message

Output

Data type

Description

q_etDiag

GD.ET_Diag

General library-independent statement on the diagnostic.

A value not equal to ET_Diag.Ok corresponds to an diagnostic message.

q_etDiagExt

ET_DiagExt

POU-specific output on the diagnostic.

q_etDiag = ET_Diag.Ok -> Status message

q_etDiag <> ET_Diag.Ok -> Diagnostic message

Return Value

Data type	Description
ST_Circle2D	Calculated circle which passes through the three specified points

Diagnostic Messages

q_etDiag	q_etDiagExt	Enumeration value	Description
OK	Ok	0	Ok
InputParameterInvalid	PointsCollinear	20	The points are located on a straight line.

Enumeration name:	Ok
Enumeration value:	0
Description:	Ok

The circle has been calculated successfully.

PointsCollinear

Enumeration name:	PointsCollinear
Enumeration value:	20
Description:	The points are located on a straight line.

Issue	Cause	Solution
-	The three points i_stPoint1, i_stPoint2 and i_stPoint3 are located on a straight line.	The three points i_stPoint1, i_stPoint2 and i_stPoint3 must not be located on a straight line.