CS 1110 Introduction to Computing using Java    Fall 2010  
9367 TR 09:05 Hollister B14 Instructors: David Gries and Lillian Lee  
9369 TR 11:15 Hollister B14 Grade: letter or S/U.   Credits: 4


23 Nov Frequently asked questions regarding A7
13 Nov Hint on debugging methods in A6
10 Sept

The Texts page has info on downloading the CD ProgramLive.

You need the Java Runtime Env. (JRE) and Java Development Kit (JDK) before DrJava will work. If you have problems on your PC, read the DrJava page, see a consultant, or email Prabhjeet Singh, ps598@cornell.edu.

Do A1 with a partner? Group yourselves on the CMS by Wednesday. Feel free to submit A1 before the deadline if you have it done --gives us more time to give feedback.

Retake quiz 1? Come to class Tuesday, 15 minutes early. Can't make it? Email gries. See Quiz page for info on what to study.

Quiz 2 is Tuesday, 14 Sept. See Quiz page for info on what to study.

09 September Warnings in DrJava
10 August Using VideoNote
10 August Can't open the DrJava jar file
10 August About labs
10 August Haven't received any CS1110 email yet?
10 August No serial number/device ID on your iClicker?
Register your iclicker, even if it's used.
10 August About the course management system
10 August Make extensions visible on your PC
10 August Seeing consultants, TAs, instructor(s)

Debugging in A6 Some of you have trouble debugging methods in A6. Here is a hint: Make use of function ImageArray.toString.

For example, suppose fuzzify isn't working. You have written a method that has loop(s) whose body averages a single pixel using something like

fuzzPixel(a, r, c);

which is supposed set a[r][c] to the average of 9 pixels surrounding and including currentIm[r][c]. But this call doesn't seem to be working. How can you find or what it is doing? Do two things:

1. Change the loop so that it processes only 20 pixels (or less), so that you don't get too much output.

2. Add print statement before and after the call so that you can see output:

System.out.println("pixel (" + r + "," + c + ") before: " + ImageArray.toString(a. getPixel(r,c)));
fuzzPixel(a, r, c);
System.out.println("pixel (" + r + "," + c + ") after: " + ImageArray.toString(a. getPixel(r,c)));

Warnings in DrJava When a Java program is compiled, warnings of various kinds may appear in the Compiler Output Pane. Generally these can be ignored. You can eliminate different kinds of warnings by doing the following:

  1. Choose (when you are running DrJava) menu item Edit -> Preferences
  2. In the preference window, choose category Compiler Options
  3. Uncheck the box for warnings you don't want to appear

Generally, we leave the top two boxes (Show Unchecked Warnings and Show Deprecation Warnings) checked and uncheck the rest. We'll explain these checked ones at the appropriate time.

VideoNote The 11:15 lecture will be filmed and placed on www.cs.cornell.edu/videonote/cornell. Along with the video comes a table of contents; click on an item and the video changes immediately to the place corresponding to the item you clicked.

Use VideoNote as a supplement to the course. Look at a video if you want to go over some part. If you have to miss a lecture because of the flu, another illness, an interview, a sports roadtrip, use VideoNote to see the lecture.

Do not use VideoNote to skip class regularly, as a prop to allow you to postpone studying, and so on. That will hurt you in the long run. Our study of the use of VideoNote shows that it can hurt rather than help the C- student who misses lots of lectures and procrastinates on studying because they feel they can catch up later with Videonote.

Together, the provost's office and the College of Engineering are spending $5,000 so that you can have access to VideoNote. Appreciate that.

Can't open the DrJava jar file. When you double-click on the DrJava jar file, that application is supposed to start. However, there may be a problem with your Windows Operating system, especially if it is Windows 7. If you have this problem, try visiting this website and downloading and installing application JarFix:


About labs. Please read these guidelines for labs carefully.

  1. You are expected to attend a lab session each week. You do not have to be formally registered in the lab you attend, but you should regularly attend the same lab. If you miss more than 3 labs (or don't do the assignment for 3 labs) without a reasonable excuse given to the Lab TA beforehand, we reserve the right to lower your grade a notch (e.g. from B to B-). We don't do this very often, but we reserve the right to do it.
  2. If you do not complete a lab the week on which it is handed out, complete it at home during the week and show it to your Lab TA the next week.
  3. Labs that are not completed by the next week will not be counted.
  4. Please do not email Profs. Gries or Lee about who to see or what to do if you missed a Lab. Talk to your LAB TA.

Haven't received CS1110 email yet but able to login to the CS1110 CMS website? The problem may be that you've set email forwarding improperly; we've received a few email bounce messages. Check that you are having mail to <your netID>@cornell.edu forwarded to a valid address.

If you also can't login to the CMS website, then the problem is that you aren't entered into the system; email Maria Witlox, as described in the CMS announcement below.

No serial number/device ID on your iClicker? This number, needed to register the clicker, can be recovered by bringing your clicker to one of the CIT Instructional Computer Labs (in Phillips 318, Upson B7, or Uris Library Tower room) between 9am and noon on weekdays, or the Academic Technology Center in the Computing and Communications Center Room 124 between 9am and 5pm on weekdays.

Register your iClicker, even if it's used. Do so by visiting http://atcsupport.cit.cornell.edu/pollsrvc . You'll login with your netID and password, and you'll need the serial number, or device ID, of your clicker, which can be found, perhaps near a "bar code", on the back (you may wish to put some invisible tape over the serial number or write it down somewhere, since the numbers can rub off). Note that each individual student in CS1110 needs their own clicker.


About the CMS (Course management system). We use a CS-designed "course management system" to manage assignments, tests, etc. The CMS for this course is at this URL: http://cms.csuglab.cornell.edu/.

When you visit the site, you will have to give your Cornell netid and password.

Fix your PCs so that extensions (like .java and .doc) ALWAYS appear. To do this, do the following: Open an explorer window. Use menu item Tools / Click on Folder Options. Click the view tab. Uncheck the box "Hide extensions for known file types".

Summaries of lectures
Please look at courseOutline.html, which summarizes what we did in lecture each time.

Seeing consultants, TAs, instructor(s)

Check here for office hours of TAs and instructor(s) and a link to the consultant calendar.

The TAs have office hours. If you need some conceptual help of any kind, go to the TAs during their office hours. Choose any TA whose office hours are convenient for you; you don't have to limit yourself to your lab TA. If you want some one-on-one time with a TA, contact the TA. They will accommodate you if they have time, but remember that they are generally taking courses too.

Consultants for CS1110 hold hours in the green room of the ACCEL Lab, which you get to through the Engineering Library in Carpenter Hall. You may spend a good deal of time programming there. The consultants are there to answer your questions. If you need help downloading and setting up DrJava, if you have a misunderstanding on an assignment, if you are having trouble debugging a program —in all such matters, ask the consultants for a quick answer. However, they will not write your program for you.