Synopsis

PDX_MSGT gdx_EvalOffsetCurveDerivs(long option, T_GDX_OFFSET_CURVE *gdx_oc, double tval, int max_derivs, double (*derivs)[3])

Purpose

Evaluate derivatives on a GDX offset curve

Description

At a given parameter value and the GDX offset curve definition, evaluate derivatives on the GDX offset curve entity. A max_derivs of 0 is equivalent to evaluating a point on the GDX offset curve entity. The GDX offset curve entity must be a valid GDX definition. A max_derivs > 3 returns zero derivative values.

Input

option

GDX_FROMLEFT

Evaluate the derivatives from the left

gdx_oc

The GDX offset curve entity data structure

tval

The parameter value to evaluate

max_derivs

The maximium derivative required

Output

derivs

The max_derivs 3D derivatives

Return

      GDX_NOERR
      Low level error return
      .fi