I am amazed that every year there are still new things that can be added and improved to Gtree. In version 4, I have added integration of R (R is a language and environment for statistical computing and graphics, see http://www.r-project.org/). Currently I am working a lot on combining GAMS with R, i.e. using the strengths of these two worlds for data calculations and manipulations. GAMS is great in optimization and R is great in statistical analysis/econometrics and graphs. Running GAMS, saving GAMS data, starting an R batch doing statistical analysis and making graphs etc., saving R data and reading data back in GAMS is easy (if you want the GAMS and R code see our website, there is documentation as well). Since I like to do all my tasks from Gtree, adding R functionality was a logical step. Also the fact that GAMS has released its first R package called “gdxrrw” that makes it easy to read and write GDX files in R is very promising (thank you GAMS for listening to us). The marriage of GAMS and R promises to be a very interesting one and the first babies are already turning up (e.g. I am working on GAMS-R graphics and GAMS-R outlier detection and I hope to add them to our website soon)…
With Gtree you can add GTREE tags to your GAMS code and hence create a tree (table of contents) of the file and organize the code and make it easier to find things. Please read Chapter 10 “Special Gtree tags” since the Gtree tag statements are extended to make even better trees.
If you have big and complex code and you work on it as an (international) group, you need a versioning system like Tortoise SVN. Gtree has Tortoise functionality, making it easy to download the last model and to commit changes to the SVN server.
Working with other peoples models and making big complex data systems in GAMS, I needed a lot of additional functionality. This was implemented in new tab pages:
As always, many small bugs have been solved (and new ones introduced ). Please let me know if you are still missing things. I already started working on version 5…
For downloading visit our website: http://www3.lei.wur.nl/gamstools