FC_Poly5Coefficients

FC_Poly5Coefficients - General Information

Overview

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

Task

Calculate the coefficient of a polynomial from the boundary conditions.

Description

Calculates the coefficients of a polynomial P which meets the following boundary conditions:

oP(i_lrX0) = i_lrY0

P(i_lrX1) = i_lrY1

oP’(i_lrX0) = i_lrM0

P’(i_lrX1) = i_lrM1

oP’’(i_lrX0) = i_lrK0

P’’(i_lrX1) = i_lrK1

The coefficients are returned in a structure of the type ARRAY[0...5] OF LREAL which may serve e.g. as an input of the function FC_Poly5Value() in order to calculate the function values of the polynomial. The following must hold: i_lrX1 > i_lrX0.

Interface

Input	Data type	Description
i_lrX0	LREAL	Left marginal point of the X interval
i_lrY0	LREAL	Required function value of the polynomial at the point i_lrX0
i_lrM0	LREAL	Required slope of the polynomial at the point i_lrX0
i_lrK0	LREAL	Required curvature of the polynomial at the point i_lrX0
i_lrX1	LREAL	Right marginal point of the X interval
i_lrY1	LREAL	Required function value of the polynomial at the point i_lrX1
i_lrM1	LREAL	Required slope of the polynomial at the point i_lrX1
i_lrK1	LREAL	Required curvature of the polynomial at the point i_lrX1

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
ARRAY[0 .. 5] OF LREAL	List of the coefficients, with the element 5 being the coefficient of the highest order and the element 0 being the coefficient of the lowest order.

Diagnostic Messages

q_etDiag	q_etDiagExt	Enumeration value	Description
OK	Ok	0	Ok

Enumeration name:	Ok
Enumeration value:	0
Description:	Ok

The coefficients have been calculated successfully.