package ngordnet.ngrams;
import java.util.List;
import java.util.TreeMap;
* An object for mapping a year number (e.g. 1996) to numerical data. Provides
* utility methods useful for data analysis.
* @author Josh Hug
public class TimeSeries extends TreeMap
private static final int MIN_YEAR = 1400;
private static final int MAX_YEAR = 2100;
// TODO: Add any necessary static/instance variables.
* Constructs a new empty TimeSeries.
public TimeSeries() {
* Creates a copy of TS, but only between STARTYEAR and ENDYEAR,
* inclusive of both end points.
public TimeSeries(TimeSeries ts, int startYear, int endYear) {
// TODO: Fill in this constructor.
* Returns all years for this TimeSeries (in any order).
public List
// TODO: Fill in this method.
return null;
* Returns all data for this TimeSeries (in any order).
* Must be in the same order as years().
public List
// TODO: Fill in this method.
return null;
* Returns the year-wise sum of this TimeSeries with the given TS. In other words, for
* each year, sum the data from this TimeSeries with the data from TS. Should return a
* new TimeSeries (does not modify this TimeSeries).
* If both TimeSeries don’t contain any years, return an empty TimeSeries.
* If one TimeSeries contains a year that the other one doesn’t, the returned TimeSeries
* should store the value from the TimeSeries that contains that year.
public TimeSeries plus(TimeSeries ts) {
// TODO: Fill in this method.
return null;
* Returns the quotient of the value for each year this TimeSeries divided by the
* value for the same year in TS. Should return a new TimeSeries (does not modify this
* TimeSeries).
* If TS is missing a year that exists in this TimeSeries, throw an
* IllegalArgumentException.
* If TS has a year that is not in this TimeSeries, ignore it.
public TimeSeries dividedBy(TimeSeries ts) {
// TODO: Fill in this method.
return null;
// TODO: Add any private helper methods.
// TODO: Remove all TODO comments before submitting.