When sizes are changing dynamically, it is often desirable to know something about the physical size and layout of a device under design, no matter how abstract the available information may be. DELTAE has an option to write a `geometry' file for this purpose. Selecting it causes a .geo file to be written that contains X-Y pairs suitable for plotting with your favorite graphics software. When this file is given to graphing software, the resulting plot is representative of a half cross-section of a cylindrical device similar to the model. The figure below is an annotated plot made from the geometry file for our final example of the Hofler refrigerator:
Figure IV.2: Geometry of Hofler refrigerator example .
We have labeled all of the segments, except for the ducts, with their numbers and types. DELTAE generates little `tick' marks to identify the breaks between segments. The lines down to zero on either end are generated by the VSPEAker and HARDEnd segments, respectively. The height at most points is proportional to the square root of the area. The COMPLiance is the exception; it looks nothing like Hofler's sphere. It is a symbolic cylinder that has length equal to radius (sort of-factors of pi are ignored) proportional to the specified volume. (Some models, such as those with active branches, are not supported properly by geometry files yet.)