Welcome to the TurboGrumbler--Release: August 2011

The "TurboGrumbler.exe" file is an Optional Add-On for the GRumbler, and provides faster search times. The TurboGrumbler will only be required by users working with very large class sizes (i.e. over 1000 students) and/or wanting to conduct extensive and exhaustive searches for optimal solutions.

[Mac users: Please note that there is no Mac-compatible version of the TurboGrumbler.]

To use the TurboGrumbler, you should first download and install the latest (zipped) version of GRumbler.xlsm (use "save" option and then unzip the file). Then follow the instructions below for downloading and installing the TurboGrumbler.exe file.

The explanations on this page are designed for users already familiar with the purpose and operations of the GRumbler. (Others should probably refer to the GRumbler page first).

Who needs the Turbo Version?

The TurboGrumbler takes a few extra steps to install but offers greater computational power than the GRumbler. If you want the simplest possible installation, and deal with class-sizes smaller than 300, then you should probably stick with the GRumbler.

The GRumbler relies solely on Excel macros to perform all its computations. With the TurboGrumbler installed, when users launch a new search, the <GRumbler.xlsm> file will call up a precompiled executable program <TurboGrumbler.exe>, which does all the hard mathematical work, rather than relying on Excel macros for this computationally-intensive task.

The search algorithm for <TurboGrumbler.exe>, coded in C++, runs roughly 20 times as fast as searches performed by <GRumbler.xlsm> itself... which means, unless you are dealing with extremely large classes, it's usually all over before you can say "Captain Jack Sparrow."

The GRumbler looks and behaves basically the same way, whether or not the <TurboGrumbler.exe> file is installed, and will be perfectly familiar to users of earlier GRumbler versions. If the <GRumbler.xlsm> file detects that the TurboGrumbler has been installed, when it comes time to conduct a search the GRumbler automatically passes the TurboGrumbler all the data needed to conduct the search, waits for it to complete the search, and then imports the results and shows them on the 'Search Engine' tab in the normal way. The User only deals directly with the worksheet file <GRumbler.xlsm>.

To try the TurboGRumbler for yourself

First, make sure you have downloaded the latest version of the GRumbler (August 2011 or later). It might be wise to delete other, older versions of the GRumbler from your machine, to avoid confusion. The TurboGrumbler only works with versions dated August 2011 or later.

Download the (zipped version of) executable file TurboGrumbler.exe here (choose the "save" option, and then unzip the file). (Latest update: 30th July 2011)

Where you then place the GRumbler and TurboGRumbler files, and how they get linked together, is important. Please follow these steps:

  1. Choose some out-of-the-way location, and place both files [GRumbler.xlsm & TurboGrumbler.exe] there: You might create a new directory, called "Grumbler", under "My Documents," and place both files there. Or put them into some other existing directory that you're unlikely to delete. However, you should avoid using any directory location that requires "Administrator Rights" to access, because under some Operating Systems <TurboGrumbler.exe> won't work from there. For instance, in Windows 7, you should avoid placing them anywhere under "Program Files" or "ProgramData", or anywhere close to system files. Also, under Windows XP, if you have a partitioned drive, it seems to be important to choose a location on the C: drive.
  2. Launch the <exe> file, by double-clicking its icon or filename. The "Console Screen" will appear (it should be bright green), and it will tell you that TurboGrumbler has created a textfile, called <Where-am-I.txt> containing the Directory Path. It also explains how to adjust the Console Screen color-balance in order to get the right display appearance when TurboGrumbler runs a search. Follow those instructions, and then press the space bar and the Console Screen will close.
  3. Open the worksheet file <GRumbler.xlsm>. If you see warning pop-ups, consent to "Enable Editing" and "Enable Content". Username: Also, the first time you open the file, a dialog box will appear asking you to enter your name, which will thereafter appear in the “Username” box on the Main Menu. The GRumbler does not use your name for any other purpose.
  4. The GRumbler should automatically detect the presence of <TurboGrumbler.exe>, as long as both files are in the same directory. The directory path will appear in cell B90 of the GRumbler's 'Main Menu' tab, down below the 'Occasional Use Buttons.' The 'Main Menu" will also indicate, at cell J14, that the TurboGrumbler is "Installed and Available." You won't have to open <TurboGrumbler.exe> yourself ever again, unless you decide to move it to a different directory location. The <GRumbler.xlsm> worksheet will be doing the calling, and you'll be dealing only with the <GRumbler.xlsm> file. The set-up procedure is now complete, and you can check the functioning of the TurboGrumbler by running the normal demonstration using a fictional class, as described in the standard GRumbler Instructions file.
  5. Once you're done with the Demo, erase all data from the 'Students Detail' tab. When you have finished the demonstration, scroll down to the "Occasional Use" Buttons of the "Main Menu" tab, and press "Erase all data from Students Detail worksheet." Return to the "Main Menu" tab (from the "Students Detail" tab), and press "Load Student Data into Search Engine." There isn't any student data, so this effectively cleans out the "Search Engine" tab for you.
  6. Save as Master Copy: Now save and close <GRumbler.xlsm>. This file will now act as your Master Copy of the GRumbler. You can make as many copies of it as you like, and paste them into your working directories (probably with your course files), wherever you want to use the GRumbler. It is important that you leave the file <TurboGrumbler.exe> in its out-of-the-way location, because that's where the <GRumbler.xlsm> file expects to find it. Once the set-up procedure has been followed, and <GRumbler.xlsm> knows where the <TurboGrumbler.exe> is located, the two files no longer need to be in the same directory. <TurboGrumbler.exe> stays where you originally placed it, and you can move or copy <GRumbler.xlsm> to any directory location you like.

Additional Information:

The standard GRumbler Instructions provide a detailed explanation of the underlying approach.

If you should choose to move the <TurboGrumbler.exe> file to a new location, you will need to repeat the set-up procedure by double-clicking on its icon or filename in its new location. Follow the instructions on the Console Screen to reset the color mix for comfortable viewing (as these settings are directory specific).

Then paste the new directory path from the file <Where-am-I> to cell B90 of <GRumbler.xlsm>'s "Main Menu" tab. Alternatively, if you move <GRumbler.xlsm> into the same directory as <TurboGrumbler.exe> and then open <GRumbler.xlsm>, it will detect the presence of TurboGrumbler and automatically update the directory path information in Cell B90.

Happy TurboGrumbling. I'd be happy to hear how it goes for you.

Malcolm Sparrow

Email: malcolm_sparrow@harvard.edu