COGENT was first implemented on workstations running versions of UNIX. It has recently been ported to Windows. The two systems are currently quite distinct, and though they share many features, there are also features that are idiosyncratic to each version. Nevertheless, models developed one version can generally be edited and run under the other version. (There are four exceptions to this, as described below: Windows COGENT models that employ RGB colour specifications; Unix COGENT models that employ indexed colour specifications; Unix COGENT models that employ interactive activation networks; and Unix COGENT models that employ user-defined properties.)

Differences between the systems
(Unix COGENT 1.10.04 and Windows COGENT 1.02.07)

Features that are present in different ways in both versions

  1. In Windows COGENT the model editor and the project manager are stand-alone applications. In Unix COGENT they are both part of a single tool.
  2. In Windows COGENT models are stored as a single file (with .cog extension). In UNIX COGENT models are stored as a hierarchy of files stored in a single directory. Windows COGENT includes facilities to import models developed under Unix COGENT, and facilities to export projects for reading by Unix COGENT.
  3. In Windows COGENT interaction with a running model is through the run buttons located on the top of each model window. Output from Prolog is piped to special windows that are normally not visible. In Unix COGENT interaction is through a special purpose window, and output is shown on a panel of that window.
  4. Windows COGENT uses a "notebook with tabs" to display the different information associated with each object. Unix COGENT uses a pull-down menu to select each view.
  5. Windows COGENT uses fixed names for the various views of objects (e.g., "Initial Contents"). Unix COGENT uses names that vary with the object type (e.g., "Diagram", "Rules and Condition Definitions", etc.).
  6. Printing in Windows COGENT uses standard Windows printer drivers. In Unix COGENT, printing a model generates PostScript or HTML. The user then has full control over what happens to the output file.
  7. In Windows COGENT, printing prints the current tab. In Unix COGENT, what gets printed is set through an options dialogue.
  8. In Windows COGENT, Analogue Buffers may contain RGB colour specifications. In Unix COGENT, such specifications are not possible, but colours can be specified by an index (0-26) into COGENT's colour map. Both systems allow a subset of colours to be specified by name (e.g., red, blue, green, ...), but Windows COGENT models that use RGB specifications or Unix COGENT models that use colour map indices will not translate properly between operating systems.

Features in Unix COGENT that are not in Windows COGENT

The Project Manager

  1. The history window has space for a one-line description of a project. This description is always visible, regardless of which tab is being viewed.
  2. Right clicking on a model node pops up a menu of model-related commands.
  3. The project manager includes an archive facility.

The Model Editor

  1. Unix COGENT has a set of configurable options that allow several aspects of the system's behaviour to be customised.
  2. Each box has a one-line description. This description is always visible, regardless of which tab is being viewed.
  3. Right clicking on a subobject pops up a menu of appropriate commands.
  4. Compound boxes can be viewed in "Message Matrix" view, showing traffic between subboxes. This view of compounds is not available in Windows COGENT.
  5. Rules, elements, etc., can be selectively ignored and reinstated.
  6. Rules, elements, etc., that have been ignored can be edited using the standard editors.
  7. Unix COGENT includes one additional box type: the interactive activation network. Unix models using such boxes cannot be translated into Windows COGENT.
  8. It is possible to define additional properties for all boxes, and make model execution dependent upon the values of these properties. Note the UNIX COGENT models containing such properties cannot at present be loaded by WinCOGENT.
  9. It is possible to define conditions within buffers. (It is likely that this "feature" will be removed if/when Knowledge Base boxes are introduced.)
  10. It is possible to import text files of rules, elements, etc., into a box, and to export a box's contents to a text file. (Experienced users may be happier using a standard text editor to edit box contents, especially if a box contains lots of similar elements. This feature makes this possible.)
  11. It is possible to run a "syntax check" on a model. This basically checks that all the right arrows are included. (It is possible to create rules, then delete the arrows that licence those rules. The syntax check feature allows the user to hunt down such perversions.)
  12. It is possible to create and run experiment scripts.
  13. It is possible to change the class of a box.

Features in Windows COGENT that are not in Unix COGENT

The Project Manager

  1. It is possible to include any file in a research programme (not just files corresponding to COGENT models).
  2. It is possible to manually edit the research programme history view (by adding or deleting arrows, and by dragging model nodes to any desired position).
  3. It is possible to import and export projects to/from Unix COGENT format.

The Model Editor

  1. It is possible to name a box without opening it (by selecting it and then typing ctrl-R).

Bugs and Oddities

Windows COGENT 1.02.07

  1. It's possible to create malformed condition definitions by inserting subconditions when a condition isn't specified.
  2. Pasting a box onto the canvas yields a copy of the box directly underneath the original and with the same name. As a result, there is no obvious sign that anything has happened. (The copy should have a slightly different name, and be offset a little.)
  3. Focus switches from the Run|Options window to the root window when the Run|Options window is closed. Instead, focus should revert to the window that was on top when the Run|Options window was opened.
  4. If I minimise a box, then open it from the box selector, the minimised box doesn't maximise, as it probably ought.
  5. Application icons disappear from the registry when I upgrade.
  6. Numeric precision appears to be fixed at 10. It should be possible to set this by a property, and it should default to something more like 2 or 3.
  7. Closing a rule editor with the X on the top of the window seems to save the changes before closing. Closing a buffer editor in the same way doesn't appear to save the buffer element.
  8. Display updating is still unsatisfactory, and could be improved along the lines of Unix COGENT, by monitoring file sizes.
  9. Table buffers use a different font from other buffers. Why?
  10. Help isn't context-sensitive. HTML system supports it, but WinCOGENT provides only one entry point.

Unix COGENT 1.10.04

  1. An XView error sometimes occurs when you close a model from the model's project's history window's Done button. This appears to happen when and only when the user left clicks in the model's box/arrow editor after selecting one of the panel buttons from the top of the window (e.g., Run... or Help...). It has something to do with shifting focus.
  2. Widgets for text fields don't always work correctly if the text being typed in overflows the available window space. Overflow text should just result in the appearance of a little scroll button and scrolling of part of the text off the widget (either to the left or the right). Sometimes, however, the insertion cursor is also (incorrectly) moved to the middle of the text being entered.
  3. Archive extraction should check for an existing directory before over-writing it.
  4. The archive/extract functions should be able to handle project names containing unusual characters (e.g., spaces). At the moment they don't because they just feed the project name as a character string straight to the Unix tar command (and if this character string contains spaces then those spaces are interpreted as signifying the end of the project's name).
  5. If a box's class is changed and the box's data is then reloaded (before the change of class is saved), the box's properties will be correctly updated, but the box's icon and mode menu will not be updated. (Reported by RC on Nov 4, 1998.)
  6. The location of syntax errors in imported files is incorrectly reported. (Reported by RC on Jan 24, 1999.)
  7. Cutting and pasting boxes between models tends to cause a fatal error. Basically arrows from the pasted box may still point to boxes in the original model, even if that original model is no longer in memory. (Reported by RC on Jan 24, 1999.)
© The COGENT Group (1997, 1998)