maphist.py

# Implementation of the Histogram ADT using a Hash Map.

from hashmap import HashMap

class Histogram:
    def __init__( self, catSeq ):
        self._freqCounts = HashMap()
        for cat in catSeq:
            self._freqCounts.add( cat, 0 )

    def getCount( self, category ):
        assert category in self._freqCounts, "Invalid histogram category."
        return self._freqCounts.valueOf( category )

    def incCount( self, category ):
        assert category in self._freqCounts, "Invalid histogram category."
        value = self._freqCounts.valueOf( category )
        self._freqCounts.add( category, value + 1 )

    def totalCount( self ):
        total = 0
        for cat in self._freqCounts:
            total += self._freqCounts.valueOf( cat )
        return total

    def __iter__( self ):
        return iter( self._freqCounts )