Gri: Evolution of Gri

Evolution of Gri 1: Introduction 2: Simple example 3: Fancy example 4: Running Gri 5: Programming Gri 6: General Issues 7: X-Y Plots 8: Contour Plots 9: Image Plots 10: Examples 11: Handling Data 12: Gri Commands 13: Gri Extras 14: Evolution of Gri 15: Installing Gri 16: Gri Bugs 17: System Tools 18: Acknowledgments 19: License 20: Newsgroup 21: Concept Index | # 14: Evolution of Gri Keeping Up To Date: You should keep your Gri up-to-date Keeping old Versions: Saving old reliable copies of Gri Incompatibilities: Locating incompatibilites between versions History: Changes made to Gri ## 14.1: Keeping up to date Keeping your version of Gri up-to-date is good for two reasons: (1) makes it easier to get bugs fixed (since the author normally repairs bugs in only the most recent version) and (2) lets you take advantage of new features see History. For instructions on installing the new version, see Accessing. To protect yourself against changes in syntax, use the ``expecting`' command in all gri programs; this command checks the version number of Gri and summarizes any incompatibilities that have come up since you wrote the gri program; see Incompatibilities. Although it is difficult to keep a paper manual up-to-date, it's easy to keep the online manual up-to-date, so you should do that see Accessing. Furthermore, you should keep your paper copy of the commands reference card (a PostScript file called ``cmdrefcard.ps`') up-to-date at all times; download it from the FTP site ``ftp.phys.ocean.dal.ca`' whenever you get a new Gri. If you have mosaic or another WWW (world wide web) reader, you can access the Gri manual in WWW form at ``http://www.phys.ocean.dal.ca/~kelley/gri/gri1.html`' and of course you can access the FTP site ``ftp.phys.ocean.dal.ca`' from any ftp tool. ## 14.2: Keeping old versions of Gri NOTE: this section is under development and details may be wrong, especially for Linux systems. To keep from getting clobbered by my ``improvements'' to Gri, you might wish to keep old versions of Gri online. Archiving the source is a simple matter of copying files. You need to copy the executable (normally called ``/usr/bin/gri`') and the startup file (normally called ``/usr/share/gri-2.4.4/lib/gri.cmd`') to some location. Let's say, for convenience, that this location is the directory ``/usr/OLD_GRI_VERSIONS/2.4.4`'. Then, just create a shellscript named ``/usr/bin/gri-2.4.4`' that reads
    /usr/OLD_GRI_VERSIONS/2.4.4/gri -directory /usr/OLD_GRI_VERSIONS/2.4.4
## 14.3: Incompatibilites Between Versions Normally, new versions of Gri execute code written for old versions. But because Gri is under continual development, incompatibilities between versions sometimes arise see Incompatible Changes. These are always easy to get around. The example files should always be up to date, so if your program is based on one of those, you might want to check there for hints. Also, it helps to use the ``expecting version .n.`' command to keep track of changes.