Marking pivot elements in a matrix?

*To*: mathgroup at smc.vnet.net*Subject*: [mg74930] Marking pivot elements in a matrix?*From*: jackgold at umich.edu*Date*: Wed, 11 Apr 2007 02:04:22 -0400 (EDT)

Hi folks, I am writing notes for a class in which matrix manipulations is a necessary and frequent task. At present, when I wish to pick an entry of the matrix as a "pivot" I simply write "pivot on {2, 3}". It would be nice to enclose the {2, 3} entry in a square or circle to indicate it is the pivot entry. I am unable to do this. In this same vein, I often have need to put a single vertical (horizontal) line through the matrix. Mathematica provides the means for putting vertical (horizontal) lines in a matrix but it allows only the option of putting lines at every column (row). I want to be more selective, say one line just before the last column. (This is the standard way of indicating that the last column is an augmentation to the original coefficient matrix). Is there any reasonably simple way to do this?

**Follow-Ups**:**Re: Marking pivot elements in a matrix?***From:*Carl Woll <carlw@wolfram.com>