Minimum circle

How to use Spatial Searching Demo

Main Functionality

- Reset application
- Creating a new window
- Print
- Close the current window
- Quit the application

Editing

- Generate points
- Insert new points in the list
- Remove points from the list
- Modify the coordinates of the points in the list

Spatial Searching

- Nearest Neighbor of Random Generated Points
- Iso_rectangle_2 Query
- Circular Query

Reset application

Press Ctrl+N combination keys or go to File menu and choose "New". The points list will be erased, the window's visible area will be set to default. (-1, 1, -1, 1)

Create a new window

Press Ctrl+W combination keys or go to File menu and choose "New Window". A new window will appear, modifying the visible area to make the points list fit in the new window.

Print

Press Ctrl+P combination keys or go to File menu and choose "Print". The visible area on the screen will be outputed to the print device of your choice.

Close the current window

Press Ctrl+X combination keys or go to File menu and choose "Close". You may do it for any window other than the initial one, this operation will close only the one you have choosen. If you do this for the initial parent window, it will close the others too.

Quit the application

Press Ctrl+Q combination keys or go to File menu and choose "Quit". When you quit the application, all the windows you have created will be destroyed.

Generate points

To generate points, go to Draw menu and choose "Generate points" or press Ctrl+G combination keys. This action will generate random points uniformly distributed in the open disc with radius 1. Each time you do this action, new points will be added to the list, the old set of point being updated and not erased.

Insert new points in the list

Left click on the "Input point" layer. Be sure there is no layer activated in standard toolbar that eat events. To be sure, press the arrow button situated on the standard toolbar. Left Click anywhere on the application's drawing area (the black rectangle) to insert the point. The new point is inserted in the list. To insert more than one point, keep clicking on the rectangle without deactivating the "Input point" layer. To deactivate this layer, just press the arrow button situated on the same toolbar.

Remove points from the list

(1)Left click on the "Move/Delete point" layer. If the "Input point" layer was active, it will deactivate itself. (2)Right click on the drawing area (the black rectangle) near an existing point. A popup menu will apear and the nearest point will be highlighted. If the popup doesn't appear, press the arrow button on the "standard toolbar" to deactivate all layers that could eat the events. (3)Choose "Delete". The point will be removed from the list. To delete more than one point, repeat the process from (2) to (3). To deactivate this layer, just press the arrow button situated on the same toolbar.

Modify the coordinates of the points in the list

(1)Left click on the "Move/Delete point" layer. If the "Input point" layer was active, it will deactivate itself. (2)Right click on the drawing area (the black rectangle) near an existing point. A popup menu will apear and the nearest point will be highlighted. (3)Choose "Move". From this moment, the point will move as you move the mouse. (4)Left click on the drawing area will position the point at the mouse coordinates. You may repeat the process from the step (2) to (4). To deactivate this layer, just press the arrow button situated on the same toolbar.

Nearest Neighbor of Random Generated Points

Go to Computation menu, and choose "Neighbor Search". This action will generate 30 random points uniformly distributed in the half-open square with side length 2 centered at the origin. The generated points are displayed in yellow color and the distance to the nearest neighbor will be displayed as a red segment.

Iso_rectangle_2 Query

Left click on the "Input Iso_rectangle" layer. Be sure there is no layer activated in standard toolbar that eat events. To be sure, press the arrow button situated on the standard toolbar. Left click anywhere on the application's drawing area (the black rectangle) to define the first corner of the rectangle. Release the mouse button and move the mouse to define the second corner. Press the left mouse button where you want to define the second corner. You will see the points matching the query in red. You may repeat the operation multiple times.

Circular Query

Left click on the "Input Circle" layer. Be sure there is no layer activated in standard toolbar that eat events. To be sure, press the arrow button situated on the standard toolbar. Left click anywhere on the application's drawing area (the black rectangle) to define the center of the circle. Release the mouse button and move the mouse to define the radius. Press the left mouse button where you want to define the radius. You will see the points matching the query in red. You may repeat the operation multiple times.

Last modified: Tue Jul 8 15:57:05 MEST 2003