adding the 3 provided files

hws/03_matrix_class/README.txt

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+HOMEWORK 3: MATRIX CLASS
+
+
+NAME:  < insert name >
+
+
+COLLABORATORS AND OTHER RESOURCES:
+List the names of everyone you talked to about this assignment
+(classmates, TAs, ALAC tutors, upperclassmen, students/instructor via
+LMS, etc.), and all of the resources (books, online reference
+material, etc.) you consulted in completing this assignment.
+
+< insert collaborators / resources >
+
+Remember: Your implementation for this assignment must be done on your
+own, as described in "Academic Integrity for Homework" handout.
+
+
+ESTIMATE OF # OF HOURS SPENT ON THIS ASSIGNMENT:  < insert # hours >
+
+
+
+ORDER NOTATION:
+For each of the functions below, write the order notation O().
+Write each answer in terms of m = the number of rows and n = the
+number of columns.  You should assume that calling new [] or delete []
+on an array will take time proportional to the number of elements in
+the array.
+
+get
+
+set
+
+num_rows
+
+get_column
+
+operator<<
+
+quarter
+
+operator==
+
+operator!=
+
+swap_rows
+
+rref (provided in matrix_main.cpp)
+
+
+
+TESTING & DEBUGGING STRATEGY: 
+Discuss your strategy for testing & debugging your program.  
+What tools did you use (gdb/lldb/Visual Studio debugger,
+Valgrind/Dr. Memory, std::cout & print, etc.)?  How did you test the
+"corner cases" of your Matrix class design & implementation?
+
+
+EXTRA CREDIT: 
+Indicate here if you implemented resize() for extra credit.  
+Also document the order notation for your resize() function.
+
+
+
+MISC. COMMENTS TO GRADER:  
+(optional, please be concise!)
+

hws/03_matrix_class/matrix_main.cpp

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+// =======================================================
+//
+// IMPORTANT NOTE: Do not modify this file
+//     (except to uncomment the provided test cases 
+//     and add your test cases where specified)
+//
+// =======================================================
+
+
+#include <iostream>
+#include <fstream>
+#include <cmath>
+#include <cassert>
+#include "Matrix.h"
+
+#define __EPSILON 0.0000000001 //Need this to compare doubles because representation.
+
+void SimpleTest(); //Some basic tests
+void StudentTest(); //Write your own test cases here
+void ExtraCreditTest(); //Write this if you write resize()
+
+
+//Function to test a ton of matrices at once.
+void BatchTest(double start, double step, unsigned int rows, unsigned int cols,
+               unsigned int num);
+
+//Quick function that returns if two doubles are very similar to each other.
+bool double_compare(double a, double b);
+
+//Uses Gauss-Jordan elimination to create a Reduced Row Echelon Form matrix.
+Matrix rref(const Matrix& m);
+
+int main(){
+	SimpleTest();
+	std::cout << "Completed all simple tests." << std::endl;
+
+	//Uncomment this to allocate a lot of 100x100 matrices so leaks will be bigger.
+	/*
+	BatchTest(100,0.1,100,100,50);
+	std::cout << "Completed all batch tests." << std::endl;
+	*/
+
+	StudentTest();
+	std::cout << "Completed all student tests." << std::endl;
+
+	//Uncomment this if you write the resize() function.
+	/*
+	ExtraCreditTest();
+	std::cout << "Completed all student extra credit tests." << std::endl;
+	*/
+	return 0;
+}
+
+////////////////Test functions//////////////////////
+//Some basic tests
+void SimpleTest(){  //well behaved getrow/read after
+	//Default constructor
+	Matrix m1;
+	assert(m1.num_rows() == 0 && m1.num_cols() == 0);
+
+	//Copy constructor
+	Matrix m2(3,4,0);
+	assert(m2.num_rows() == 3 && m2.num_cols() == 4);
+
+	Matrix m2_copy(m2);
+	assert(m2_copy.num_rows() == 3 && m2_copy.num_cols() == 4);
+	m2_copy.set(1,1,27);
+	double d0;
+	assert(m2.get(1,1,d0));
+	assert(double_compare(d0,0.0));
+	assert(m2_copy.get(1,1,d0));
+	assert(double_compare(d0,27));
+
+	//Equality and Inequality
+	Matrix m3;
+	assert(m1 == m3);
+	assert(m1 != m2);
+
+	//Printing
+	std::cout << "Empty matrix:";
+	std::cout << m1 << std::endl;
+
+	std::cout << "Zeroed 3x4 matrix:";
+	std::cout << m2 << std::endl;
+
+	std::cout << "One after the other:";
+	std::cout << m1 << m2 << std::endl;
+
+	//Set & get
+	Matrix m5(4,4,2);
+	Matrix m6(4,4,12);
+	assert(m6.set(2,1,7));
+	assert(m6.set(3,3,11));
+	double d1;
+	assert(m6.get(2,1,d1));
+	assert(d1==7);
+
+	//Addition
+	std::cout << "Adding m5 and m6" << std::endl;
+	std::cout << m5 << m6 << std::endl;
+
+	Matrix m7;
+	m7 = m5;
+	Matrix m8(m5);
+	assert(m7 == m8);
+
+	assert(m7.add(m6));
+	std::cout << "The result" << std::endl;
+	std::cout << m7 << std::endl;
+
+	double* r1 = NULL;
+	r1 = m7.get_row(2);
+	assert(r1[0] == 14 && r1[1] == 9);
+
+	delete [] r1; //Remember we need to clean up dynamic allocations.
+
+	Matrix m9(3,6,0);
+	m9.set(0,0,1);
+	m9.set(0,1,2);
+	m9.set(0,2,1);
+	m9.set(0,3,1);
+	m9.set(1,0,2);
+	m9.set(1,1,3);
+	m9.set(1,2,-1);
+	m9.set(1,4,1);
+	m9.set(2,0,3);
+	m9.set(2,1,-2);
+	m9.set(2,2,-1);
+	m9.set(2,5,1);
+
+	std::cout << "Attempting Gauss-Jordan reduced row echelon form." 
+		  << m9 << std::endl;
+	Matrix m12 = rref(m9);
+	std::cout << m12 << std::endl;
+	double comparison_value;
+	assert(m12.get(0,3,comparison_value));
+	assert(double_compare(comparison_value,0.25));
+	assert(m12.get(0,1,comparison_value));
+	assert(double_compare(comparison_value,0.0));
+	assert(m12.get(1,5,comparison_value));
+	assert(double_compare(comparison_value,-3.00/20));
+	assert(m9.get(0,3,comparison_value));
+	assert(double_compare(comparison_value,1.0));
+	assert(m9.get(0,1,comparison_value));
+	assert(double_compare(comparison_value,2.0));
+	assert(m9.get(1,5,comparison_value));
+	assert(double_compare(comparison_value,0.0));
+
+	Matrix m11(3,4,0);
+	m11.set(0,0,1);
+	m11.set(0,1,2);
+	m11.set(0,2,3);
+	m11.set(0,3,4);
+
+	m11.set(1,0,5);
+	m11.set(1,1,6);
+	m11.set(1,2,7);
+	m11.set(1,3,8);
+
+	m11.set(2,0,9);
+	m11.set(2,1,10);
+	m11.set(2,2,11);
+	m11.set(2,3,12);
+
+	std::cout << "M11 to be quartered: " << std::endl;
+	std::cout << m11 << std::endl;
+
+	Matrix* ma1 = NULL;
+	ma1 = m11.quarter();
+	assert(ma1 != NULL);
+
+	std::cout << "UL: " << std::endl << ma1[0] << std::endl;
+	std::cout << "UR: " << std::endl << ma1[1] << std::endl;
+	std::cout << "LL: " << std::endl << ma1[2] << std::endl;
+	std::cout << "LR: " << std::endl << ma1[3] << std::endl;
+
+	for(unsigned int i=0; i<4; i++){
+		assert((ma1[i].num_rows() == 2) && (ma1[i].num_cols() == 2));
+	}
+
+	//Upper Left
+	assert(ma1[0].get(0,0,comparison_value));
+	assert(double_compare(comparison_value,1));
+	assert(ma1[0].get(1,1,comparison_value));
+	assert(double_compare(comparison_value,6));
+
+	//Upper Right
+	assert(ma1[1].get(0,0,comparison_value));
+	assert(double_compare(comparison_value,3));
+	assert(ma1[1].get(1,1,comparison_value));
+	assert(double_compare(comparison_value,8));
+
+	//Lower Left
+	assert(ma1[2].get(0,0,comparison_value));
+	assert(double_compare(comparison_value,5));
+	assert(ma1[2].get(1,1,comparison_value));
+	assert(double_compare(comparison_value,10));
+
+	//Lower Right
+	assert(ma1[3].get(0,0,comparison_value));
+	assert(double_compare(comparison_value,7));
+	assert(ma1[3].get(1,1,comparison_value));
+	assert(double_compare(comparison_value,12));
+
+	delete [] ma1;
+}
+
+//Write your own test cases here
+void StudentTest(){
+
+}
+
+//Write this if you write resize()
+void ExtraCreditTest(){
+
+}
+
+
+////////////////Utility functions//////////////////////
+
+/*  Function that quickly populates a rows x cols matrix with values from     
+ *  start in increments of step. Does this num_times times.
+ */
+void BatchTest(double start, double step, unsigned int rows, unsigned int cols,
+               unsigned int num){
+	Matrix* m_arr = new Matrix[num];
+	for(unsigned int i=0; i<num; i++){
+		m_arr[i] = Matrix(rows,cols,0.0);
+		unsigned int curr_elem = 0;
+		for(unsigned int j=0; j<rows; j++){
+			for(unsigned int k=0; k<rows; k++){
+				m_arr[i].set(j,k,start+(step*curr_elem));
+				curr_elem++;
+			}
+		}
+	}
+	delete [] m_arr;
+}
+
+//Quick function that returns if two doubles are very similar to each other.
+bool double_compare(double a, double b){
+	return (fabs(a-b) < __EPSILON);
+}
+
+/*  Uses Gauss-Jordan elimination to create a Reduced Row Echelon Form matrix.
+ *  These are some good and some bad variable names.
+ *  See how much harder it makes it to follow the code?
+ *  The lack of comments doesn't help either.
+ */
+
+Matrix rref(const Matrix& m){
+	Matrix ret(m);
+	unsigned int curr_col = 0;
+	double dummy;
+	for(unsigned int i=0; i<ret.num_rows(); i++){
+		bool col_all_zeros = true;
+		//while(col_all_zeros && col_all_zeros < ret.num_cols()){
+		while(col_all_zeros && curr_col < ret.num_cols()){
+			for(unsigned int scan_i = 0; scan_i < ret.num_rows(); scan_i++){
+				ret.get(scan_i,curr_col,dummy);
+				if (!double_compare(dummy,0.0)){
+					col_all_zeros = false;
+					break;
+				}
+			}
+			if(col_all_zeros){
+				curr_col += 1;
+			}
+		}
+		if(curr_col>=ret.num_cols()){
+			return ret;
+		}
+
+		ret.get(i,curr_col,dummy);
+		if(double_compare(dummy,0.0)){
+			//Swap with a nonzero row
+			for(unsigned int scan_i = i+1; scan_i < ret.num_rows(); scan_i++){
+				ret.get(scan_i,curr_col,dummy);
+				if(!double_compare(dummy,0.0)){
+					ret.swap_row(scan_i,i);
+					break;
+				}
+			}
+		}
+
+		//Now we know ret i,curr_col is non-zero so we can use it as a pivot.
+		double pivot;
+		ret.get(i,curr_col,pivot);
+		for(unsigned int j=0; j<ret.num_cols(); j++){
+			ret.get(i,j,dummy);
+			ret.set(i,j,dummy/pivot);
+		}
+
+		for(unsigned int row_i = 0; row_i < ret.num_rows(); row_i++){
+			if (row_i == i){
+				continue;
+			}
+			double row_leading_coeff;
+			ret.get(row_i,curr_col,row_leading_coeff);
+			for(unsigned int col_j = 0; col_j < ret.num_cols(); col_j++){
+				double lhs_dummy,rhs_dummy;
+				ret.get(row_i,col_j,lhs_dummy);
+				ret.get(i,col_j,rhs_dummy);
+				ret.set(row_i,col_j,lhs_dummy - (row_leading_coeff*rhs_dummy));
+			}
+		}
+		curr_col +=1 ;
+	}
+	return ret;
+}

hws/03_matrix_class/sample_output.txt

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+Empty matrix:
+0 x 0 matrix:
+[ ]
+
+Zeroed 3x4 matrix:
+3 x 4 matrix:
+[ 0 0 0 0
+  0 0 0 0
+  0 0 0 0 ]
+
+One after the other:
+0 x 0 matrix:
+[ ]
+
+3 x 4 matrix:
+[ 0 0 0 0
+  0 0 0 0
+  0 0 0 0 ]
+
+Adding m5 and m6
+
+4 x 4 matrix:
+[ 2 2 2 2
+  2 2 2 2
+  2 2 2 2
+  2 2 2 2 ]
+
+4 x 4 matrix:
+[ 12 12 12 12
+  12 12 12 12
+  12 7 12 12
+  12 12 12 11 ]
+
+The result
+
+4 x 4 matrix:
+[ 14 14 14 14
+  14 14 14 14
+  14 9 14 14
+  14 14 14 13 ]
+
+Attempting Gauss-Jordan reduced row echelon form.
+3 x 6 matrix:
+[ 1 2 1 1 0 0
+  2 3 -1 0 1 0
+  3 -2 -1 0 0 1 ]
+
+
+3 x 6 matrix:
+[ 1 0 0 0.25 0 0.25
+  -0 1 0 0.05 0.2 -0.15
+  0 0 1 0.65 -0.4 0.05 ]
+
+M11 to be quartered: 
+
+3 x 4 matrix:
+[ 1 2 3 4
+  5 6 7 8
+  9 10 11 12 ]
+
+UL: 
+
+2 x 2 matrix:
+[ 1 2
+  5 6 ]
+
+UR: 
+
+2 x 2 matrix:
+[ 3 4
+  7 8 ]
+
+LL: 
+
+2 x 2 matrix:
+[ 5 6
+  9 10 ]
+
+LR: 
+
+2 x 2 matrix:
+[ 7 8
+  11 12 ]
+
+Completed all simple tests.
+Completed all student tests.