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 jth 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.