December 15, 2009 - On Windows Vista machines, some users have found that the init.m file to be used to set $Path and other needed commands is

C:\ProgramData\Mathematica\Kernel\init.m

October 28, 2009 - The MakeSum function, as used in Section 4.1.10 of the MathTensor book, will no longer work in Mathematica 7 unless the following is added to init.m or done at the beginning of a MathTensor session.

Unprotect[Sum]
Sum[a_] := a
Protect[Sum]

This is not needed in Mathematica 6 or lower,

November 25, 2008 - For Mathematica 7, it is now necessary to add the line

Unprotect[RiemannR]

to the init.m file - typically this file is in the Library/Mathematica/Kernel subdirectory of your user directory.

May 23, 2008 - On systems with Mathematica 6, the placement of the init.m file that needs to be read (see below) to set the $Path and other items has moved to /Library/Mathematica/Kernel/init.m (or sometimes in the Library folder in the user's home folder). On Windows machines, the appropriate init.m file is intallation dependent and may be in a place like

..\Wolfram Research\Mathematica\6.0\SystemFiles\Kernel\Packages\init.m

or

..\Application Data\Mathematica\Kernel\init.m

where the ..\ in front depends on where you have Mathematica installed.

A user recently reported this -

Have just installed MathTensor and managed to get it to load and recognise the password file. Just a couple of comments on what seems to be mac/Mathematica 6.x specific stuff that you might want to add to the install instructions before I forget!

(1) In my installation at least, there is no init.m file in the Applications/Mathematica path. Instead I used the local one in /Users/Library/Mathematica/, which I guess means I have only installed for one user and not globally. If you edit it in Mathematica you get the package editor, which seems to work fine. Sometimes the mac front end (mostly the packaging system for applications) makes it a bit difficult to see the nuts and bolts of the UNIX which is underneath! I didn't need any double slashes in the path for it to work.

(2) The password file was slightly more problematic - I tried to use the default mac TextEdit to produce an rtf and rename it, but that doesn't seem to read in Mathematica (could be the old windows/UNIX carriage return, linefeed incompatibility?) After that I tried to make a mathematica package file (.m) but that didn't work either. Finally I resorted to vim to get a really pure ASCII file, which works fine. You might like to add a comment somewhere to indicate that you need to really use a low level editor to get it to read properly? I guess emacs would work too, but I haven't tried it.

Another user sent this suggestion -

Simplified Installation Instructions suggested by Alessandro Stecchina:

We will create a MathTensor Loader notebook which will take care of all the settings required to run MathTensor. (This is written for a Windows system and might need to be modified slightly for Mac or Unix systems.)

0 - Start a new Mathematica session

1 - In Mathematica evaluate $BaseDirectory or $UserBaseDirectory. This will give you a Mathematica folder that contains an Applications folder. The Applications folder is the place to install the MathTensor package-folder. This is the recommended place for 3rd party packages in Mathematca 6.x So go ahead and place the MathTensor package-folder inside the Applications folder inside $BaseDirectory or inside $UserBaseDirectory At the conclusion you should have the structure:

...\Mathematica\Applications
     \MathTensor package folder (called mathtensor or MathTensor, or something smilar)
        \package files

-------------------------------------------------------------------------------
Unprotect[TensorQ];
$Path = Join[$Path, {$BaseDirectory <> "\Applications\mathtensor"}];
Off[Syntax::"com"];

<< mathtens.m
postfunc[x_Graphics | x_Graphics3D] := x;
postfunc[x_] := OutputForm[x];
$Post := postfunc;
--------------------------------------------------------------------------------

Some users of Mathematica 7 find that the postfunc lines above cause problems. They can be left out.

3 -Depending on your operating system or configuration, you may need to:

Replace $BaseDirectory with $UserBaseDirectory if you have installed MathTensor in $UserBaseDirectory. Replace "mathtensor" with the folder name containing the MathTensor package (for ex. MathTensor) Replace "mathtens.m" with the appropriate filename for launching MathTensor (for ex. MathTensor.m) Deepending on your operating system, you may need to slightly change the folder separators in the string "\Applications\mathtensor". Just look at how the $BaseDirectory string is made and copy the separator

4 - Save the notebook as "MathTensor Loader" (or whatever else you wish) in the folder where you keep your regular notebooks.

5 - Evaluate the cell

If all is well you have loaded MathTensor and you can do some testing to see that everything is ok. Try also:

as you see graphics cells are output in standard (graphics) form. All the rest is in OutputForm

If you like to save your work, just use the Save as... menu command and choose a name and location for your notebook. It will be saved with the loader cell inside, so next time you can just open it and launch MathTensor from it. Otherwise, every time you wish to use MathTensor from scratch, just open the MathTensor Loader notebook and evaluate the cell.

That's it!

October 1, 2007 - On Macintosh OS X systems running Mathematica 6, we have found it better to install the UNIX/Linux version of MathTensor. So, on the Macintosh CD, if you are using Mathematica 6, use the mathtensor.tar.gz file in the Mathematica 6 folder and follow the UNIX instructions below. If you are not using Mathematica 6, use the files in the other folder and follow the Macintosh instructions.

May 5, 2007 - In Mathematica 6, you will need to set the output form for tensors in a different way. See Step 5 below for more details.

July 11, 2003 - Mathematica 5 or higher differences. Some users have reported that when they move to Mathematica 5 or higher, they are having load problems with MathTensor. One is that it appears that a TensorQ function has been added in Mathematica 5 or higher which will conflict with MathTensor's TensorQ function and give errors when loading. The quick fix for this is to just do