Choosing a Coordinate System
Graphical VDA Tools allow you to position graphics objects and text in the display area using one of two coordinate systems: Normalized and Data. The selection you make can affect the appearance of output you send to an output device.
Device Coordinates
Graphics objects and text are positioned on a coordinate system that matches the coordinate system of the device on which the view is displayed or printed. The device coordinates usually represent pixels, ranging from (0,0) in the lower-left corner to (Vx – 1, Vy – 1) in the upper-right corner, where Vx and Vy are the total number of pixel rows and columns for the device.
The device coordinate system can be useful in an image view if you want to position a graphic at or near a specific pixel value.
note | If you select Device coordinates, you can get undesired results upon sending the view to an output device. For example, a title that you position in device coordinates on your view window will not appear at the same place on the printed copy unless the printer has exactly the same number of pixels as the view window. The best way to ensure that graphic objects and text will appear where you want them in printed hardcopy is to select Data or Normalized coordinates. |
Normalized Coordinates
Graphics objects and text are positioned on a coordinate system that ranges from (0,0) in the lower-left corner of the view window to (1,1) in the upper-right corner.
The normalized system is useful if you want to position an object, such as a title, in a position relative to the entire view window. For example, normalized coordinates enable you to position a title in the center of the view window and have it also appear in the center of the printed page. With the normalized coordinate system, you can be sure that the text or graphic object will appear in its proper position when you print the contents of a view.
Data Coordinates
Graphics objects and text are positioned on a coordinate system that has a range identical to the range of the displayed data.
The data coordinate system can be useful if you want to position a graphic or text object at or near a specific data point. With the data coordinate system, you can be sure that the text or graphic object will appear at or near the same data point when you print the contents of a view.
