An *n* by *m* matrix of *(0,1)* indicator variables,
where *n* is the length of `classification`

and *m* is
the number of unique values or symbols in `classification`

.
Columns are labeled by the unique values in `classification`

,
and the `[i,j]`

th entry is *1* if `classification[i]`

is the *j*th unique value or symbol in sorted order

`classification`

.
If a `noise`

value of symbol is designated, the corresponding indicator
variables are relocated to the last column of the matrix.