Drawing an Ellipse

Function Description

The ellipse command is used to create an ellipse. The application provides two methods for drawing an ellipse: one is an inscribed ellipse of a drawn rectangle, and the other is an oblique ellipse drawn using the semi-major axis and semi-minor axis.

Function Entry

  • Features tab -> Objects group -> Polygon drop-down list -> Ellipse.

Operation Instructions

Inscribed Ellipse of a Drawn Rectangle
  1. In the Features tab's Objects group, click the Polygon drop-down button, select the Inscribed Ellipse option, and an ellipse cursor appears.
  2. Move the mouse to the map, and you can see that as the mouse moves, the coordinate values of the point are displayed in real-time in the subsequent parameter input box. In the parameter input box, enter the starting point coordinates of the ellipse (you can switch between the two parameter input boxes by pressing the Tab key) and then press the Enter key to determine the starting position of the ellipse.
  3. Move the mouse, and you can see the blue temporary ellipse changing size as the mouse moves. As the mouse moves, the width and height of the rectangle are displayed in real-time. In the subsequent parameter input box, input the parameter values and press the Enter key to execute the input and determine the position of the ellipse.
  4. Click the right mouse button to cancel the current drawing operation.

Drawing an Oblique Ellipse

  1. In the Features tab's Objects group, click the Polygon drop-down button, select the Oblique Ellipse option, and an ellipse cursor appears at this time.
  2. Move the mouse to the map, and you can see that as the mouse moves, the coordinate values of the point are displayed in real-time in the subsequent parameter input box. In the parameter input box, enter the starting point coordinates of one semi-axis (either the semi-major axis or semi-minor axis) of the oblique ellipse (you can switch between the two parameter input boxes by pressing the Tab key) and then press the Enter key to determine the starting position of the semi-axis of the oblique ellipse, i.e., the position of the center.
  3. Move the mouse, and the map will display in real-time the length of the line connecting the mouse position to the starting point of the semi-axis and its angle with the positive X-axis (you can switch between the two parameter input boxes by pressing the Tab key). In the parameter input box, enter the length and angle values, and press the Enter key to execute the input, completing the drawing of one semi-axis of the oblique ellipse.
  4. Continue moving the mouse, and the map will display in real-time the length of the line connecting the other semi-axis of the oblique ellipse to the starting point of the semi-axis (the semi-axis starting point determined in the previous step). In the parameter input box, type the length of this semi-axis and press the Enter key to complete the drawing of the oblique ellipse.
  5. Click the right mouse button to cancel the current drawing operation.
Notes:

Ellipses drawn in a line dataset are ordinary line objects, only recording the coordinates of each node on the line. However, ellipses drawn in a CAD dataset are parametric objects, recording corresponding parameters such as the center, semi-major axis, and semi-minor axis.