|  |  | 4.6 Symbolic and absolute attributes

## 4.6 Symbolic and absolute attributes

Attributes such as color, line width, dash style, mark size, or text size, can be either absolute (a number, or a set of numbers specifying a color) or symbolic (a name). Symbolic attributes must be translated to absolute values by a style sheet for rendering.

One purpose of style sheets is to be able to reuse figures from articles in presentations. Obviously, the figure has to use much larger fonts, markers, arrows, and fatter lines in the presentation. If the original figure used symbolic attributes, this can be achieved by simply swapping the style sheet for another one.

The Ipe user interface can be switched between displaying absolute and symbolic attributes (using Absolute attributes in the View menu). When creating an object, it takes its attributes from the current user interface settings, so if you are in symbolic mode, the object gets symbolic attributes, otherwise it gets absolute attributes. Absolute attributes have the advantage that you are free to choose any value you wish, including picking arbitrary colors using a color chooser. In symbolic mode, you can only use the choices provided by the current style sheet.

The choices for symbolic attributes provided in the Ipe user interface are taken from your style sheet. The standard style sheet is deliberately short, to encourage users to figure out how to make their own.

The settings for grid size and axis angle can be switched between symbolic and absolute independently. The current setting has no influence on objects being created.

|  |  | 4.6 Symbolic and absolute attributes