Category Archives: GAMS

Using org-mode in outline-mode

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I have written about using org-mode in gams-mode in an earlier post. Gams-mode lets you structure your gams file using headings and subheadings. These headings can be (partially) collapsed. The structure of your file could look like this:

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You can now cycle through the structure using Shift-Tab. Tab opens a section:

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This is a great help in complex files.

Gams-mode has another great outline feature for the listing file. Instead of putting a normal comment with a “*” in front, one writes a display statement that starts with a “@” (see the code above). We now see a nice heading … Read the rest “Using org-mode in outline-mode”

Migrating to R 3.0.0: TikzDevice and gdxrrw

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I am an avid user of R. Most of the time, I use R for preparing nice plots and tables for my LaTeX papers. For my plots, I use TikzDevice and for my tables I use xtable. Gams, my modeling software, developed a nice interface for using data from Gams in R and the other way around (see http://support.gams.com/doku.php?id=gdxrrw:interfacing_gams_and_r). When I upgraded from R 2.15 to R 3.0, I had some problems on my windows 8 machine, especially with TikZDevice. I finally managed to get it installed. The necessary trick is described on “The Stata Things” (!!!, http://enoriver.net/index.php/2013/04/12/keeping-knitr-happy-after-upgrading-to-r-3-0-0/ )
… Read the rest “Migrating to R 3.0.0: TikzDevice and gdxrrw”

GAMS and Excel: writing and checking results with automatic closing and opening

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I often use the Gams utility gdxxrw to write the results of my model simulations to Excel. In the testing phase, if you don’t know some nice tricks, this means a lot of closing and opening Excel: If the result file is open in excel, you get an error, when you try to write results to the Excel file, so you have to close Excel first and rerun your simulation. After writing the results to Excel you have to reopen the file again. Lots of keystrokes…
However, gdxxrw lets you reduce the number of strokes, by using the gdxxrw utility
… Read the rest “GAMS and Excel: writing and checking results with automatic closing and opening”

Using Windows Desktop Search to search for text in files with another extension than "txt"

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I use Windows Search quite often on my notebook to look for a file, E-Mail or a program. In Windows you just hit the Windows Key and start typing, which is very convenient.
If you want to start a program you just start typing the program name and hit enter Excel, hit the key and type “exc” and enter, and off you go.
The normal search (files or text within files) is also very powerful. Here is a site which explains the syntax: http://msdn.microsoft.com/en-us/library/aa965711(v=vs.85).aspx and here is a good article http://www.howtogeek.com/73065/learn-the-advanced-search-operators-in-windows-7/ on how to use it.
 
One problem with
… Read the rest “Using Windows Desktop Search to search for text in files with another extension than "txt"”

Outlining in Gams-Mode: Org-Mode for Gams

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The new version of Gams-mode has a new feature that I like very much. It allows you to use an outline-mode in your gams files. It is called org-mode, which is a major mode in Emacs.
 
You can outline your Gams file using sections, subsections, etc. You define sections using the following notation:
 
       *@
 
or for subsections
 
       *@@, *@@@, etc.
 
Let us have a look at the file org-minor-mode.gms. This file can be found in your gams-mode directory. This file contains all the help for gams-mode. All the help
… Read the rest “Outlining in Gams-Mode: Org-Mode for Gams”