四点，与一斜率

Synopsis

obj = GCONIC/point1,point2,point3,point4,VECT,x,y,z

Description

Creates a general conic by specifying four previously defined points and a vector which is the direction of tangency

Parameters

Parameter

Description

point1,point2,point3,point4

Four previously defined points which are on the curve. All of the points must be co-planar, however, no three of the points may be collinear. The points must be specified individually if an array is used.

VECT

Minor word that indicates that a tangent vector is to be specified.

x,y,z

The three components of a vector which may be specified individually or as an array. The specified vector represents the tangent of the conic at the first point.

Example

Creating a general conic by specifying four previously defined points and a vector which represents the slope of the conic at the first point.

Declarations

ENTITY/P(4),GC1
NUMBER/XYZ(3)
DATA/XYZ,1,2,0

Geometry Definition

P(1)=POINT/1,1
P(2)=POINT/2,1.5
P(3)=POINT/3,1.75
P(4)=POINT/4,1.875

Conic Definition

GC1=GCONIC/P(1),P(2),P(3),P(4),VECT,XYZ

General Conic Using Four Points and a Vector

Parameter	Description
point1,point2,point3,point4	Four previously defined points which are on the curve. All of the points must be co-planar, however, no three of the points may be collinear. The points must be specified individually if an array is used.
VECT	Minor word that indicates that a tangent vector is to be specified.
x,y,z	The three components of a vector which may be specified individually or as an array. The specified vector represents the tangent of the conic at the first point.