Lab 2: OpenMP & Matrix Multiplication

ECE 4122/6122 Lab 2: OpenMP & Matrix Multiplication
(100 pts)
Problem 1: Matrix Multiplication (90 pts)
Write a C++ application that can read in two matrices (A & B) from a text file using a command
line argument to specify the file path and name. The input file format is shown below. A C++
program is included to generate random sample input data files.
4 2
1.35477 8.35009
9.68868 2.21034
3.08167 5.47221
1.88382 9.92881
2 3
9.96461 9.67695 7.25839
9.8111 1.09862 7.98106
Your application must work correctly when compiled in both OpenMP mode and non-OpenMP
mode. Your application needs to multiple the two matrices together and output the multiplied
matrix to a text file called MatrixOut.txt using the same format as the input file. Use the standard
matrix multiplication technique in your application.
( https://en.wikipedia.org/wiki/Matrix_multiplication )
** Your application will also be graded on speed when compiled using OpenMP flag.
Problem 1 Turn-In Instructions:
Place all the files (*.h, *.cpp) used in your solution into a zip file called Lab2Problem1.zip and
upload to the Canvas assignment.
Problem 2: OpenMP Analysis Report (10 pts)
Upload a short essay in a text file (Lab2.Prob2.txt) describing and comparing the performance of
your application when compiled using OpenMP flag verses not using the flag. Run multiple tests
using larger and larger matrix sizes and indicate when OpenMP performed better than not using
OpenMP. What was the largest test size and what were the relative run times?
Grading Rubric
If a student’s program runs correctly and produces the desired output, the student has the potential to get a 100 on his or
her homework; however, TA’s will randomly look through this set of “perfect-output” programs to look for other
elements of meeting the lab requirements. The table below shows typical deductions that could occur.
 Execution Time is important for this lab.
AUTOMATIC GRADING POINT DEDUCTIONS PER PROBLEM:
Element Percentage
Deduction
Details
Files named incorrectly 10% Per problem.
Execution Time Up to 8% 0 pts deducted < 10x shortest time
pts deducted = (2/10) (your time/shortest time) - 2
(rounded up to whole point value, with 4 pts maximum deduction for
each problem)
Does Not Compile 30% Code does not compile on PACE-ICE!
Does Not Match Output 10%-90% The code compiles but does not produce the correct outputs.
Clear Self-Documenting
Coding Styles
10%-25% This can include incorrect indentation, using unclear variable names,
unclear/missing comments, or compiling with warnings. (See
Appendix A)
LATE POLICY
Element Percentage Deduction Details
Late Deduction Function score – 0.5 * H H = number of hours (ceiling function) passed
deadline
***You are free to post solution times on pizza so that other students can gauge their run times.
Appendix A: Coding Standards
Indentation:
When using if/for/while statements, make sure you indent 4 spaces for the content inside those. Also make
sure that you use spaces to make the code more readable.
For example:
for (int i; i < 10; i++)
{
 j = j + i;
}
If you have nested statements, you should use multiple indentions. Each { should be on its own line (like the
for loop) If you have else or else if statements after your if statement, they should be on their own line.
for (int i; i < 10; i++)
{
 if (i < 5)
 {
 counter++;
 k -= i;
 }
 else
 {
 k +=1;
 }
 j += i;
}
Camel Case:
This naming convention has the first letter of the variable be lower case, and the first letter in each new word
be capitalized (e.g. firstSecondThird). This applies for functions and member functions as well! The main
exception to this is class names, where the first letter should also be capitalized.
Variable and Function Names:
Your variable and function names should be clear about what that variable or function is. Do not use one
letter variables, but use abbreviations when it is appropriate (for example: “imag" instead of
“imaginary”). The more descriptive your variable and function names are, the more readable your code will
be. This is the idea behind self-documenting code.
File Headers:
Every file should have the following header at the top
/*
Author: your name
Class: ECE4122 or ECE6122 (section)
Last Date Modified: date
Description:
What is the purpose of this file?
*/
Code Comments:
1. Every function must have a comment section describing the purpose of the function, the input and
output parameters, the return value (if any).
2. Every class must have a comment section to describe the purpose of the class.
3. Comments need to be placed inside of functions/loops to assist in the understanding of the flow of
the code.