The Pixel Coordinate System

• point (0,0) is in the upper left corner
• x-coordinates increase from left to right
• y-coordinates increase from top to bottom
• pixel coordinate system is defined in the constructor of the window

The User Coordinate System

• (0,0) in bottom left corner
• x-coordinates increase from left to right
• y-coordinates increase from bottom to top
• defined by three doubles: xmin, xmax, ymin
• scaling factor: w/(xmax-xmin) where w is the width of the window in pixels
• ymax=ymin+h*scaling where h is the height of the window in pixels
• user coordinate system can be set by W.init(), the default values are xmin=0, xmax=100, ymin=0

The window type provides operations for translating user coordinates into pixel coordinates and vice versa. See Manual Page Windows for details. The Basic Example of How to Use window defines a window with pixel x-coordinates between 0 and 500, pixel y-coordinates between 0 and 600, and user x- and y-coordinates between -1000 and 1000.

See also:

Windows and Panels

Manual Page:

Manual Page Windows