Subroutine Type

Utility/Data Access

Definition

Evaluate a B-spline or user-written curve created with the Reference_ParamCurve entity.

Use

The function can be called by any user-defined subroutine.

Calling Syntax

Fortran

CALL GTCURV (id, alpha, iord, array, istat)

C

c_gtcurv(id, alpha, iord, array, istat)

Python

[array, istat] = py_gtcrv(id, alpha, iord)

MATLAB

[array, istat] = m_gtcrv(id, alpha, iord)

Input Arguments

[integer] ID

The identifier of the corresponding Reference_ParamCurve.

[double precision]ALPHA

The independent parameter alpha at which the curve is to be evaluated.  For B-splines, alpha must satisfy -1 <= alpha <= 1.

For curves defined using CURSUB, alpha must satisfy MINPAR <= alpha <= MAXPAR.

[integer] IORD

The variable that specifies the order of the derivative returned by GTCURV as follows:

IORD

Meaning

0

Returns the curve coordinate.

1

Returns the first derivative with respect to alpha.

2

Returns the second derivative with respect to alpha.

Output Values

[double precision] ARRAY

The array of three elements as shown below:

IORD

Array First Element

Array Second Element

Array Third Element

0

x

y

z

1

2

All elements are evaluated at alpha.

[int] ISTAT

Variable that indicates the success or the reason for the failure of GTCURV.