# Synopsis

PDX_MSGT igeo_Check104QForm(long option, MDA_PTR db_ptr, double zero_tolerance, int *conic_form)

# Purpose

Check IGES conic entity(104) coefficients for valid form.

# Description

Performs the check specified in the IGES standard for the form of the IGES conic entity. The check is performed by computing 3 Q values(Q1, Q2, Q3) and based on the following determines the form of the conic: Q2 > 0 and Q1 * Q3 < 0 - conic_form = IGEO_ELLIPSE Q2 < 0 and Q1 != 0 - conic_form = IGEO_HYPERBOLA Q2 = 0 and Q1 != 0 - conic_form = IGEO_PARABOLA

The test for <=> 0 is tested to the zero_tolerance value where zero_tolerance is a value close to 0.0. If a valid conic_form can not be determined the conic_form is set to IGEO_UNKNOWNCONIC.

# Input

## option

The option( Not Used)

## db_ptr

The IGES 104 entity database pointer

## zero_tolerance

The close to zero tolerance value

# Output

## conic_form

The form of the conic IGEO_ELLIPSE - conic is an ellipse IGEO_HYPERBOLA - conic is a hyperbola IGEO_PARABOLA - conic is a parabola IGEO_UNKNOWNCONIC - conic form is unknown

# Return

          IGEO_NOERR
          Low level error return
          .fi