public double lookupPosterior( int value ) {
		TldFernFeature found = table[value];
		if( found == null ) {
			return 0;
		}
		return found.posterior;
	}
public double lookupPosterior ( int value ) { TldFernFeature found = table [ value ] ; if ( found == null ) { return 0 ; } return found . posterior ; }
Looks up the posterior probability of the specified fern.  If a fern is found its posterior is returned
otherwise -1 is returned.

NOTE: How unknown values are handled is a deviation from the paper.

@param value The fern's value
@return Fern's posterior probability.  If the value is known then return -1