Using Abstract Data Types – 65 course points
This assignment consists of one part to exercise your ability to work with Strings.
Refer to our Programming Assignments FAQ for instructions on how to install VSCode, how to use the command line and how to submit your assignments.
Programming
Write a program and submit on Autolab. We provide this ZIP FILE containing ScenarioAnalysis.java. Update and submit the file to Autolab. Observe the following rules:- DO NOT use System.exit().
- DO NOT add project or package statements.
- DO NOT change the class name.
- DO NOT change the headers of ANY of the given methods.
- DO NOT add any new class fields (instance variables).
- ONLY display the result as specified by the example for each problem.
- DO NOT print other messages, follow the examples for each problem.
- You may USE the StdOut library.
Vehicle scenario analysis (65 points) The purpose of this assignment is to build an analysis model to explore what-if scenarios when buying a new car. We will consider two types of vehicles on the market:
- Gasoline powered vehicles that operate solely using gasoline.
- Fully electric vehicles that operate solely on battery-stored power and use no gasoline. The batteries are charged by plugging in to an external power source.
Considering Cost
Some of the main considerations that factor into the decision when looking for a car might include:
Cost
Convenience
Driving experience
Environmental reasons
Of the factors above, which ones can be quantified in some way? Which are more qualitative preferences? In this case, convenience and driving experience are qualitative, but cost and environmental impact (in terms of CO2 emission) can be quantified. To build a model to help with your decision, we’ll begin with the things that can be quantified. Since it is most familiar, let’s start with cost.
To simplify our model assume leased cars only. To lease a car we consider the amount due at signing, the number of months for the entire lease, the monthly cost, the milage allowance in 12 months, and the excess mileage cost per mile. We also consider the price of gas for gasoline-powered vehicles and electricity for eletricity-powered vehicles to drive the cars for the lease term.
Considering Carbon
Many people choose to buy an electric car, not because of cost but out of concern for the environment. This is a benefit that is difficult to fully capture, but certain things like greenhouse gas emissions can be measured.
Greenhouse gases (GHGs) trap heat in the Earth’s atmosphere and are believed to contribute to global climate change. Carbon dioxide (CO2) is the main GHG produced by human activity, and the two major human activities responsible for CO2 emission are electric power generation and combustion of fossil fuels for transportation. You can read a little more about CO2 emission on the EPA website.
According to the EPA, there are 8.887 kg of CO2 released with the combustion of each gallon of gasoline. This is the amount of CO2 coming out the tailpipe of a gas powered vehicle.
This means that we can estimate the total CO2 emitted over the three-year lease of a vehicle. Assuming the vehicle consumes 1 gallon of gas for every 34 miles and that the lease allowance milage is 12,000 miles per year, we can compute the number of gallons of gasoline needed to drive an estimated 36,000 miles and multiplying by 8.887kg/gal as follows:
36,000mi/(34 mi/gal) x 8.887 kg/gal = 1,058.82 gal x 8.887kg/gal = 9,409.76kg.
To drive 36,000 miles, the vehicle uses 1,058.82 gallons of gasoline and produces 9,409.76 kg of CO2.
You can do this same calculation for any gas-powered car by plugging in the number of miles driven (M) and the fuel efficiency of the vehicle in miles per gallon (N).
To figure out how much CO2 is emitted in generating the electricity to charge the battery of an electricity-powered car over a three-year lease, let’s begin by estimating the total energy for battery charging needed to drive 36,000 miles. Assuming that it takes 60kWh to fully charge the car and that the car can drive for 238 miles per charge we estimate the total energy needed for battery charging needed to drive 36,000 miles is:
36,000 mi/(238 mi/charge) x 60 kWh/charge = 9,075.6 kWh.
According to the EPA’s Power Profiler website, 998.4 pounds of CO2 are emitted per mWh on average across the United States.
Converting units, there are about .45kg per pound, resulting in the following total CO2 emission in kg to power the car:
9,075.6 kWh * [ 998.4 lbs CO2/ MWh * 1MWh/1000Kwh * 0.45kg/lb ] = 4077.5 kg/CO2
Given all of this, we now have the capability to estimate the CO2 emission resulting from driving an electric vehicle. It boils down to plugging in the number of miles driven (M), battery storage capacity (E), and the driving range on a charge (R) into the following equation.
This equation looks hairy, but we can deconstruct it by noticing that the quantity in brackets on the left is electricity consumption, and the quantity in brackets on the right is essentially just unit conversions to get us from kWh of electricity to kg of CO2.
Given Equation 2 and Equation 1 from the previous section, we can figure out the CO2 emissions from any gas-powered car and any electric car, and that’s what we will do now.
The Assignment
You will need to read a substantial amount of code to understand the classes in this assignment. Always start reading at the main() method. The assignment code comprises of the following Abstract Data Types.
For more information read the respective Java files.
- Lease stores information about the a vehicle’s lease. The amount due at signing, the number of months for the lease, monthly cost and the number of miles per year.
- Fuel stores information related to the type of fuel the vehicle operates with. For electric-powered vehicles it includes the amount of kWh it takes to charge the battery in addition to the amount of miles/charge or miles/gals for gas-powered vehicles.
- Vehicle includes fuel and lease information in addition to CO2 emitted during the lease length, other costs (oil change or home charger), fuel cost and finally the total cost to have the vehicle for the lease length.
- ScenarioAnalysis allows us to compare several vehicles given the current gas and electricity prices. The class reads the text file vehicles.txt which contains vehicle data. You can update this file to add new vehicles.
In this assignment you will implement the computeCO2EmissionsAndCost() method in the ScenarioAnalysis class:
public void computeCO2EmissionsAndCost () {}
This method computes the CO2 emissions, fuel, lease and total cost for every vehicle in the vehicles array:
- Use the equations from the previous section to compute CO2 emissions for gas or electric-powered vehicles.
- Fuel cost is the cost, in dollars, to fuel the vehicle for the length of the lease. Assume the vehicle is driven the total mileage allowance allotted by the lease.
- Lease cost, in dollars, includes the payment due at signing plus all the monthly payments for the extension of the lease.
- Total cost, in dollars, include all costs of leasing and driving the vehicle for the length of the lease. It includes lease costs, fuel costs, and other costs.
Use the main method provided in the ScenarioAnalysis class to test your method.
This assignment can be used to compare among several car options a buyer is considering.
Update the vehicles.txt file according to lease information, fuel, etc. The file has either gas or electric powered vehicles. The format is as follow:
| gas | name | cash due at lease signing | lease length in months | monthly lease cost | mileage allowance per 12 months | miles per gallon | cost of oil change | |
| electric | name | cash due at signing lease | lease length in months | monthly lease cost | mileage allowance per 12 months | miles per kWh/charge | kWh per charge | cost of home charger |
Check out this video explaining the assignment
Before submission
- Collaboration policy. Read our collaboration policy here.
- Update @author. Update the @author tag of the files with your name, email and netid.
- Submitting the assignment. Submit ScenarioAnalysis.java via the web submission system called Autolab. To do this, click the Assignments link from the course website; click the Submit link for that assignment.
Getting help
If anything is unclear, don’t hesitate to drop by office hours or post a question on Piazza. Find instructors office hours by clicking the Staff link from the course website. In addition to office hours we have the CAVE (Collaborative Academic Versatile Environment), a community space staffed with lab assistants which are undergraduate students further along the CS major to answer questions.