As shown here, Word 2007’s equation interface provides a maximum matrix size of 3×3:
So, what if you need a 3×4, 4×4, 4×3, or some other size matrix? Are you out of luck? Not at all.
Begin by inserting a 3×3 matrix as shown above. What you see in your document is shown here, minus the “Click here” balloon:
Click as shown to drop down the control menu for the equation object for the choices shown at the right. Click on Linear.
This now exposes the ugly syntax for creating a matrix using the linear syntax:
So, what does this mean? Well, first of all, you’re not seeing the entire picture. What’s missing is the full syntax. If you could see the full syntax, you’d see:
& corresponds to columns, and @ corresponds to rows. For x & characters, you get x+1 columns. For y @’s, you get y+1 rows.
When modifying the syntax to add additional columns, it’s easy. Just add a & as shown here:
Now, right-click the equation and choose Professional, and you’re rewarded with:
Right-click again and choose Linear, however, and you’ll see that Word automatically completed the syntax for you:
That’s because ragged matrices aren’t allowed. What’s a ragged matrice? Had they been permitted, the modified matrix using (&&&@&&@&&) would’ve looked something like this:
So, if you wanted a 4×4 matrix, what would you do? Insert a 3×3 and modify like so:
Notice that I’ve added another column, and I’ve said to include 4 rows in that column. But, I haven’t added additional &’s in the other parts of the syntax specification. Nonetheless, when I right-click the equation and choose Professional, I now get this:
If I now flip this back to linear, I see that Word graciously filled out the needed syntax for me:
When going the other way â€“ shrinking an existing matrix â€“ you would need to completely modify the syntax. Word isn’t smart enough to sense that you’ve removed an & and now want a bunch more removed. But, frankly, if you want a smaller matrix, just use the built-in user interface.