Project 5 – Matrix Calculator

ECE2036 
Project 5 – Matrix Calculator

Introduction. We will extend our previously developed ComplexCalculator to provide for the simple matrix operations add, subtract and multiply (we won’t do divide). To implement this, we will create a class called Matrix
that implements a two–dimensional matrix. We will implement several constructors, including one that populates the
matrix with data from a character string. To describe a matrix with a string, we use parenthesis to delineate the rows
of the matrix. For example:
(1,2,3),(4,5,6),(7,8,9)
would represent the matrix:
1 2 3
4 5 6
7 8 9
All the rules from previous calculator program apply, such as only a single operator per input line, lines starting with
an operator use the prior result at the first operand, etc. We will also use a Not A Matrix flag in our Matrix class to
indicate that the matrix is invalid. This would be set when the size of the matrices being added or multiplied are not
compatible or when the matrix is unintialized.
Since we don’t know at compile time how many rows or columns a matrix object will have, we must use dynamic
memory management to allocate and return memory for the matrix elements. For simplicity in this assignment, we
will simply allocate a one dimensional array of elements of size “Number Rows * Number Columns”. The memory
should be allocated in the matrix constructor if the size is known. The memory should also be freed in the matrix
destructor.
Specific Program Requirements.
1. You must define and implement a Matrix class, with a constructor with a string argument, to construct a
matrix with initial contents. In this case the size of the matrix is apparent from the input string. Additionally,
you will need a second constructor with two unsigned int’s specifying an m x n matrix initialized with all zeros
(to be used for results in arithmetic expressions).
2. Since your Matrix class allocates memory in the constructor (for the matrix elements), you MUST implement
a destructor that frees the memory, plus a copy constructor and an assignment operator.
3. You must implement a IsNaM function that returns a boolean true/false indicating whether the matrix is Not a
Matrix. As mentioned above, a matrix is Not a Matrix if it is the result of arithmetic operators of incorrect size.
4. The Matrix class must implement a member function At that accepts two Index t arguments (row and
column) and returns a non-const reference to an Element . If properly implemented this At function can act
like a “Getter” when on the right-hand-side of an assignments, or a “Setter” when on the left-hand-side of an
assignment.
5. All operator overloads must be implemented as member functions, and all operator overloads must have const
for both left-hand-side and right-hand-side.
6. Values within the matrix should be stored as type Element t. This is defined to be an int in matrix.h, but
we could change to a double later and not require any code changes.
7. Any variable intending to represent an array index should be of type Index t to make the code more readable.
8. Matrix arithmetic should be performed using operator overloading.
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9. You must implement a Print() member function. The printed matrix must have the column values aligned
right–justified, such as:
25 123 5 0 0
0 2 3 0 0
0 999 10 0 0
0 0 0 1 1
3 0 0 0 3
To make the assignment a bit easier, you can assume that no individual element value has more than 5 digits and
all numbers are positive.
10. You will likely find that your main loop in matrix-calc.cc is nearly identical to the main loop in the
original complex-calc.cc from the earlier program.
Design Philosophy. Your program design should be as simple as possible, but no simpler. 1
Resources. There are a number of files that are given to you. These are all on the deepthought19.cc.gatech.edu
system, and you will copy these to your own directory (instructions as to how to do this are below).
1. A skeleton matrix-calc-skeleton.cc program that is a starting point. It contains the subroutine to read
a line from standard in and call the string parser. Your main loop should exit when an empty line is encountered
(when the string parser returns a count of zero).
2. Skeleton Matrix.h describes the requirements for the Matrix class. You should implement the required
functions in Matrix.cc.
3. string-parse.h and string-parse.cc are provided for string parsing. Note the ToElement conversion function that converts a string to an integer Element t. Also note that anything inside a pair of
parens is not a separator. Thus, parsing “(1,2,3),(4,5,6)” with a separator of comma gives two substrings, “(1,2,3)” and (4,5,6)”. To reduce those substrings to three individual integers you of course use
RemoveParens and then SringParse again.
4. A Makefile for building the executable binary.
5. A second executable called test-matrix runs several canned test cases.
6. test-matrix-out.txt is the expected results from running test-matrix.
Your program can be compiled and tested on any available computing platform that has a C++ compiler. The
instructor and TA will compile and test your program on the jinx linux systems. Be sure to put your name on the
source code in the comments section.
Copying the Project Skeletons
1. Log into deepthought19.cc.gatech.edu using ssh and your prism log-in name.
2. Copy the files from the ECE2036 user account using the following command:
/usr/bin/rsync -avu /nethome/ECE2036/MatrixCalculator .
Be sure to notice the period at the end of the above command.
3. Change your working directory to MatrixCalculator
cd MatrixCalculator
1Paraphrased from quote by Albert Einstein
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4. Copy the provided matrix-calc-skeleton.cc to matrix-calc.cc as follows:
cp matrix-calc-skeleton.cc matrix-calc.cc
5. At this point, you can run the make program to compile the skeletons. Of course it won’t do anything useful
since you have not implemented your Matrix class.
6. Use emacs or vi to edit the files as needed to implement your program.
7. You can test your program against a fixed set of inputs in file input.txt as follows:
./matrix-calc < input.txt
8. The expected outputs from this are found in file output.txt
Checking for Memory Leaks and Other Memory Problems This type of program with dynamic memory management is particularly difficult to get implemented correctly. Often programs that are buggy and mis-manage memory
will in fact work properly and produce right answers in some cases. However, we still need to correctly manage all
dynamically allocated memory. On the linux systems, there is a nice tool called valgrind that helps us identify and
fix problems with memory management.
To use valgrind, you simply run the valgrind program passing as arguments the name of the program to be tested
and all paramenters to your program. For the matrix calculator, you would likely say:
valgrind --tool=memcheck ./matrix-calc < input.txt
The output of valgrind is sometimes hard to read; so we will go over this in class. We will run valgrind on your
program when grading, and to get a 100% you must get a “Clean Valgrind” (with no errors reported).
Turning in your Project. The system administrator for the jinx cluster has created scripts that you are to use to
turn in your project. The script is called riley-turnin (or davis-turnin or hamblen-turnin) and is
found in /usr/local/bin, which should be in the search path for everyone. From your home directory (not the
MatrixCalculator subdirectory), enter:
riley-turnin MatrixCalculator
This automatically copies everything in your MatrixCalculator directory to a place that we can access (and
grade) it. Of course you use klein-turnin if you are in his section.
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