Return unique groups.
c=unique(a)
c=unique(a,ignorecell)
c=unique(a,{'ignoreid','ignorename'})
UNIQUE returns the unique set of groups in the IMAT_GROUP array A.
The optional cell array of strings IGNORECELL can contain the following strings, which specify which properties to ignore when making the comparisons.
| String | Action |
| 'ignoreid' | ignore the group id |
| 'ignorename' | ignore the group name |