Objects to tag, specified as an array of graphics objects. Each graphics object must
have a Tag property.
Tag, specified as a character vector, string scalar, or character matrix.
To use the same tag for all the objects in obj, specify
tagstr as a character vector or a string scalar.
To use a different tag for each object in obj, specify
tagstr as a character matrix. The number of rows in the
matrix must match the number of objects in obj.