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Exam Instructions

The following actions must be performed to pass the take-home exam. See below for more details.

  • Download your exam
  • Solve the problems
  • Correct your solutions
  • Return your solutions and get your grades

Exam procedure in summary

You will pass EL1150 by succesfully completing a take-home exam. Once you have downloaded your exam, you will have 72 hours to solve the problems and return your solutions.

Note that you have exactly three days (72 hours) to solve these assignments. No answers will be accepted if they are received more than 72 hours after you downloaded your exam. The Bilda system will keep track of the time.

When you feel ready, you can do your exam using the following steps:

  • Follow the link marked "Bilda" and log in.
  • You will then get access to the Matlab file "marker.p". Download this file and save it in a folder in you Matlab search path.
  • In Matlab, run marker and follow the instructions.

The program marker will assign you four exam problems. Once you have solved the problems, you will use the function marker to check your solutions. When marker has checked your solution, it will produce a vector with five (5) integers. Submit these numbers by the exam webpage no later than 72 hours after you claimed your assignments. You will then directly get your results. The maximal score is four points, and you will need two points to pass the exam. You can only submit your answers ONCE. If you have problems, contact the course responsible.

Bilda (download and hand in exam)

Exam details

After you have entered your personal number in the form and pressed the button marked "Download exam'', you will get access to the file marker.p . Download the file to your computer, and save it in a folder that is in your Matlab search path.

1. Doing the Exam

The file marker.p is a (coded) Matlab function that generates and corrects your exam. To generate your problem set, start Matlab and type marker in your Matlab Command Window. Marker will then produce the following instructions.

>> marker
MARKER Delivers exam problems and marks the solutions.

To claim a problem, type:

marker( PROBLEM, BIRTHDATE )

where

PROBLEM - The index of the problem, i.e. 1, 2, 3 or 4.
BIRTHDATE - Your 6 digit birth date as yymmdd.

Example: marker( 1, 760206 ); % Your first problem

There are four problems for You to solve. Note that BIRTHDATE determines
this set of problems. You will not pass the exam unless You solve the
problem set given by Your own birthdate!

Your solutions shall be MATLAB functions contained in files with extension
'.m' in the current directory, or on the MATLAB search path.

When You are ready to hand in Your solutions, mark the solutions by
executing

CODE = marker( 0, BIRTHDATE );

The numbers given in the CODE vector shall be entered on the exam home page in Bilda.

Good Luck!

In case you get the following error message

>> marker
??? Undefined function or variable 'marker'.

please move marker.p either to your current Matlab working directory (you will find out which one this is by typing pwd in the Matlab Command Window) or any other directory in the Matlab search path.

2. Getting your Problem Set

The exam consists of four problems. You will have to request them separately using the command

>> marker( problem_number, birthdate)

where problem_number is the number 1, 2, 3 or 4 and birthdate is a six-digit number describing your birthdate. For example, if you are born on the 10th of February 1976, you type

>> marker(1, 760210)

to request your first problem, marker(2, 760210) to request your second problem, etc. When called in this way, marker generates a problem description on the form

----------------------------------------------------------------------
Sort numbers in descending order!
----------------------------------------------------------------------
Write a function that creates a column vector s, that contains the elements
of a ector x sorted in descending order (from largest to smallest).

Syntax: s = dsort(x)
------------

where s is the output vector and
x is the input vector.

Basic functionality:

>> x = [1 5 2 3 9 4]

x =

1 5 2 3 9 4

>> s=dsort(x)
s =
9
5
4
3
2
1

Try to avoid loops!

A correct solution gives one point if it passes a test similar to the
example above.
----------------------------------------------------------------------

In this case, your task is to write a Matlab function dsort (whose file name is dsort.m) that takes a vector x as input and produces a sorted version s as output.

3. Exam Tips and Tricks

  • Read the instructions! Make sure that you solve the problem exactly as requested. It may be worthwile to print out the problem description text and read it carefully. For example, if you were asked to generate dsort described on the previous page, make sure that you sort the numbers in descending order, and that the output vector is a column vector.
  • Follow the syntax! Use the same function name, ensure that your function takes the same number of inputs and generates the right number of outputs. For the dsort example, make sure that you write a function that takes one input argument (a vector) and generates one output argument (a column vector). Also make sure that your function is saved in a file compatible with the function name: for dsort, you should save your function as dsort.m
  • Write functions, never scripts: marker expects that your solutions are written as functions, and will fail you if you try to construct soutions based on script files.
  • Test your function! Make at least sure that your function solves the example problem given in the problem definition. For dsort, generate at least the vector x in the example text and make sure that your solution generates the same output vector. Note that your solution will be tested for a wide range of inputs, and that it is not enough that it solves the specific example problem stated in the problem text. It is often worthwile to make up other test examples by yourself to verify that your function works in general.
  • Make sure that you generate the full problem set! The exam consists of four problems, and you will have to generate them separately using the procedure described above.

4. Grading your Solutions

Once you have solved your problems, you will use marker to grade your solutions. The syntax is

>> code=marker(0, birthdate)

Monitor the text generated when you run marker(0,birthdate):

  • If marker reports that it cannot find one of your solutions, make sure that your solution files are in the same directory as marker
  • If marker generates error messages on screen, go back and test your solutions. Make sure that your solutions do not generate any error messages when called with test examples (use the one given in the problem description text, but also try to make up other examples).
  • marker will display a status indicator of how far it got correcting your solutions. This indicator will count up to 100 % for each of the tasks you solved. A value of 100 % simply means that marker is done grading this task and does by no means indicate anything about the correctness of your solution.

5. Returning the Exam and Getting your Grades

When you use marker for correcting your exam, it will generate a vector with five (5) integers. For example

>> code=marker(0,760210)

code = 203 952 825 336 424

To grade your solutions, you will have to enter these numbers in the form in the Bilda system.

Manual check of the solution

Manual corrections are in general NOT carried out. Exceptions to this rule will be considered only in special cases, such as a major system failure.

Getting Help

If you have any problems with running marker, please contact the course responsible.