TriGrid

TriGrid is a modelling system for building Triangular Grids. It was originally developed with oceanographic modellers specifically in mind, but is of general utility.

Open Source Future for TriGrid (Posted January 2, 2002)

This is the future web site of open source TriGrid. TriGrid's Open Source home is at sourceforge.net/projects/trigrid/. TriGrid is released under the GPL, so that it may remain available for use and further development. Initial deployment will be assisted for up to 6 months (to end June 2002) by Adrian Dolling (formerly of Channel Consulting Ltd.), principal developer/maintainer of TriGrid since about 1990.

I expect the TriGrid user community to become actively involved in support and evolution of TriGrid, including its documentation. Like any open source project, success will depend on self-interested volunteering! TriGrid is already a mature product, but maintained by a small number of individuals. There will be some culture changes needed to make open source work. I do not know if the community cares sufficiently to take this on, but have had a number of expressions of interest. I have not been ready to hand TriGrid source to one or more individuals...as that would, I believe guarantee that it quickly became unavailable. This is TriGrid's best chance!

The source is mostly Fortran77, with small C/C++ modules to provide GUI interface support for MS Windows and for unix/X-window systems. Only minor software adaptations will be required to remove licencing code. Channel will be able to provide some assistance with this step. The MS Windows build requires Digital (now Compaq or HP!) Fortran, and MS Visual C++ compilers.

Status of these web pages... (Posted January 2, 2002)

This is very much a first cut deployment. None of the references to www.channel.bc.ca have been removed (they will be updated to reference trigrid.sourceforge.net instead). None of the download files are available. Their locations will be also be moved to trigrid.sourceforge.net. The active links however have been left as placeholders.

Documentation

An html version of the TriGrid User Manual is under development here.

Distribution Centre

The current release of TriGrid is called TG97. It is available now (27 Jan 1998) for the MS Windows 95 and NT platforms. The unix releases will follow shortly.

This release contains over 250 new and updated features, including:

New implementation of Delauney Triangulation (1000 times faster!, More robust!)

Dynamic triangulation embedded in graphical editors makes grid generation a much more efficient process

Nearest node or edge detection with graphical feedback if ambiguous

Tested with grids up to 1,000,000 nodes, capable of more

Geographic transformations (latitude & longitude to/from UTM)

Interactive boundary definition, validation, and sampling

Merge multiple datasets in graphical noder

DVF compiler used throughout for greater speed and correctness

Full defects database (see release notes)

Please see the release notes for full details.

The TriGrid system is currently available for both unix and PC platforms. For Intel (Windows and linux) the distribution is available in two sizes: 50,000 or 250,000 nodes. For other platforms the standard distribution is for 250,000 nodes, although it is available in sizes up to 1,000,000 on request. The following distributions are available:

TriGrid/Win32 Distribution Centre This is the 32 bit Windows version for MS Windows 95/98/2000/NT. The standard distribution is for 250,000 nodes and 26 neighbours.

The following unix distributions have not yet been updated for the TG97 release. They are the previous TG96 release.

The HP 9000 series (ftp://ftp.channel.bc.ca/pub/TriGrid/TriGrid.HP.tar.Z) archive is for the HP workstations. Built for about 200,000 nodes. Practical limit unknown, but probably capable of several million nodes.

The IBM RS6000 (ftp://ftp.channel.bc.ca/pub/TriGrid/TriGrid.RS6000.tar.Z) archive is for IBM's RS/6000 workstations. It is built for about 50,000 nodes. The practical limit is unknown.

The DEC ALPHA (ftp://ftp.channel.bc.ca/pub/TriGrid/TriGrid.ALPHA.tar.Z) archive is for DEC's ultrix operating system. Built for about 200,000 nodes. Practical limit unknown, but exceeds 300,000 nodes and 48 neighbours!

Linux (for PC, in a.out format), via ftp on request. Built for about 200,000 nodes. Practical limit unknown.

Our preferred distribution method is via our ftp site (the links above). A licence is also required to run with more than 1000 node capacity. These distributions can all be licenced after installation. The maximum capacity varies from platform to platform, and the distribution version capacity is indicated above.