# Synopsis

PDX_MSGT igeo_Eval132Derivs(long option, MDA_PTR db_ptr, IMTH_MATRIX matrix, double tval, int max_derivs, double (*derivs)[3])

# Purpose

Evaluate derivatives on an IGES Connect Point (132)

# Description

At a given parameter value between 0.0 and 1.0 inclusive, evaluate derivatives on the IGES point entity. A &a max_derivs of 0 is equivalent to evaluating a point on the IGES line entity. The IGES point entity must be a valid IGES definition. A max_derivs > 0 returns zero derivative values.

# Input

## option

### IGES_NOMATRIX

Do not apply the entity matrix to the derivatives

## db_ptr

The IGES 132 entity database pointer

## matrix

The matrix to apply to the derivatives

## tval

The parameter value to evaluate (0.0 - 1.0)

## max_derivs

The maximium derivative required

# Output

## derivs

The 3D derivatives

# Return

          IGEO_NOERR
          IGEO_INVALIDPARMVALUE
          Low level error return
          .fi