椭圆形

Synopsis

obj = ELLIPS/point,semimajor,semiminor[,ATANGL,angle][,START,angle,END,angle]

Description

An ellipse is a form of a conic and is created by specifying half of the major axis (semi-major) and half of the minor axis (semi-minor). Ellipses are created in a counterclockwise direction from the positive X axis of the work coordinate system. The start and end angles may be specified to obtain only a partial ellipse, however, if they are omitted a full ellipse is created.

Parameters

Parameter

Description

point

A previously defined point which is the center of the ellipse.

semimajor

One half of the length of the major axis.

semiminor

One half of the length of the minor axis.

ATANGL

The optional minor word ATANGL indicates that the ellipse is to be rotated about its center at a specified angle. If the ATANGL parameter is not specified, the major axis is made parallel to the X axis of the work coordinate system.

angle

The angle at which the ellipse is rotated about its center. The angle is measured in degrees from the positive X axis of the work coordinate system to the major axis of the ellipse. A positive angle rotates the ellipse counterclockwise and a negative angle rotates the ellipse clockwise.

START

The optional parameter START indicates that the starting angle for the ellipse is to be specified.

start angle

The starting angle of the ellipse as measured from the positive X axis of the work coordinate system.

END

The optional parameter END indicates that the ending angle for the ellipse is to be specified.

end angle

The ending angle of the ellipse as measured from the positive X axis of the work coordinate system.

NOTE: If the value entered for the semimajor axis is greater than the value entered for the semiminor axis, the System automatically reverses the two values.

Example

Creating an ellipse where the start and end angles have been specified, therefore a partial ellipse is created. A rotation angle (45) has also been specified.

Declaration

ENTITY/PT1,ELPS1

Geometry Definition

PT1 =POINT/0,0

Ellipse Definition

ELPS1=ELLIPS/PT1,1,.5,ATANGL,45,START,30,END,330

An Ellipse that is Truncated and Rotated

Parameter	Description
point	A previously defined point which is the center of the ellipse.
semimajor	One half of the length of the major axis.
semiminor	One half of the length of the minor axis.
ATANGL	The optional minor word ATANGL indicates that the ellipse is to be rotated about its center at a specified angle. If the ATANGL parameter is not specified, the major axis is made parallel to the X axis of the work coordinate system.
angle	The angle at which the ellipse is rotated about its center. The angle is measured in degrees from the positive X axis of the work coordinate system to the major axis of the ellipse. A positive angle rotates the ellipse counterclockwise and a negative angle rotates the ellipse clockwise.
START	The optional parameter START indicates that the starting angle for the ellipse is to be specified.
start angle	The starting angle of the ellipse as measured from the positive X axis of the work coordinate system.
END	The optional parameter END indicates that the ending angle for the ellipse is to be specified.
end angle	The ending angle of the ellipse as measured from the positive X axis of the work coordinate system.