As we have shown in the previous section, SuperEdit can operate on composite documents that consist of a number of subdocuments . A composite document itself may be seen as a list of links (path names) to files that contain raster or, optionally, vector drawings.

In order to create a sample composite document, start SuperEdit , cancel the File Open dialog and click the New button on the Main toolbar. SuperEdit displays the TCD Contents window with the only root node named unnamed1 and the empty Drawing window. Choose the CDM Add Subdocument option for the root node. Choose the SuperEdit ’s DOC subdirectory and the File Type TIFF in the Add Document File(s) dialog; select four files townmap1.tif ... townmap4.tif and click the Open button. The selected files are to be placed below the root node; watch the TCD Contents window content to assure that they really are. The Drawing window will be regenerated to show four parts of image. You can also click Image properties button on Main toolbar (or choose the CDM Properties option for the root node) and inspect Composite Document dialog as shown in the figure below.

The composite document inherits its Units from the first added subdocument’s TAF attribute file ( townmap1.taf) , and its Common Extents represent the combined area of all subdocuments.

Click the Save button on the Main toolbar and save the unnamed1 composite document as map.tcd , so that the existing townmap.tcd is not overwritten.