Matrix Calculator

[ExponentialP]

Hi all, I've hit a bit of a brick wall with a project assignment I'm working on. I understand the underlying principle of what I have to do, because I've sketched out (visualised) the functionality of the program. I am just struggling at the last hurdle.

I have to create a program that calculates the sum, product or subtraction of two entered matrices. The program allows users to:

1) enter two 2x2 matrices
2) then gives the user a choice of
operation (+ - *)
3) then outputs the answer.

I have done parts 1 and 2, its part 3 I'm stuck on.
The point of this exercise is help solidify my understanding of Multi-dimensional arrays and how they can be used within a program, as well as how they store elements in memory. So I've been using static 2D arrays for this program. I've used code from a website (exforsys.com) and it was really helpful for stages 1 and 2. The things I am trying to work through is how to perform arithmetical operations on elements within a data structure... (is this even possible).

This is a hunch I have, do I need to find some way of accessing an element in the array (maybe via its array index) then ask the program to add it to its corresponding element in the other array, then do it in a loop until the full sum is done ??. I totally understand that I will need a third 2d array which will act as an "answer" array. e.g.

Matrix Matrix Matrix
Array 1 Array 2 Array 3 (answer Matrix)
-------- -------- --------
|1,n | |5,n| |6,n|
|n,n | + |n,n| = |n,n|

** Please note that I know there is a whole library in the STL(or I think boost) for matrices, but what I would please ask anyone who reads this post to understand is that I am a student and in my syllabus libraries (STL, Boost, OpenGL) comes later in my course. I was also taught that understanding arrays thoroughly is best foundation for understanding all other data structures(De-ques, Vectors, Link-List).

The Code
=========

#include "stdafx.h"
#include <iostream>


using namespace std;

int main(array<System::String ^> ^args)
{

	// Array Declarations
	//--------------------
	const int ROW = 2;														
	const int COLUMN = 2;													
	int MatrixCalArr1[ROW][COLUMN];			// This is the declarion of the MultiD array
							// 20/05/2011: Turns out will need a MD array
							// for both matrices that will be calculated and
							// for the answer matrix 
	int MatrixCalArr2[ROW][COLUMN];			// This is the MD array for the second matrix, I'm
							// gonna use the const ints not sure if it will work
						        // is it even good practice ???
   	// int MatrixAns_Arr[ROW][COLUMN];		// This array is for the eventual answer.....


	// Array Initialisations 
	//-----------------------
	int iter1;
	int iter2;


	cout << "Welcome To The Matrix Calculator" << endl						
		 << "================================" << endl
											   << endl 
											   << endl
											   << endl;
	cout << "Please Enter values of your first matrix" << endl
		 << "----------------------------------------" << endl
	     << "*Please note you can only enter values for 2x2 matrix*" << endl
																	 << endl;

																			
	for(iter1 = 0; iter1 < ROW; iter1++)		// This is for the elements that will me placed in
																			
	for(iter2 = 0; iter2 < COLUMN; iter2++)
	{																		
		cout << "Enter The Value of Row" << iter1+1;	// This asks for the value of the rows and colums
		cout << ", Column " << iter2+1 << ":__";

		cin  >> MatrixCalArr1[iter1][iter2];		// This places the elements inside the array.
	
	}

	cout << endl;
	cout << endl;  

	cout << "First Matrix" << endl
		 << "------------" << endl;
	for(iter1 = 0; iter1 < ROW; iter1++)
	{
		cout << endl;

		for(iter2 = 0; iter2 < COLUMN; iter2++)
	
			cout << MatrixCalArr1[iter1][iter2];
	}

	cout << endl;
	cout << endl;
	cout << "Please Enter values of your second matrix" << endl
		 << "----------------------------------------"  << endl;


	// Array Initialisation Matrix 2

																		   
																		
	int iter3;
	int iter4;

	for(iter3 = 0; iter3 < ROW; iter3++)

	for(iter4 = 0; iter4 < COLUMN; iter4++)
	{							// This is section of code will now ask for the arrays elements 
		cout << "Enter The Value of Row" << iter3+1;	// This asks for the value of the rows and colums
		cout << ", Column " << iter4+1 << ":__";

		cin  >> MatrixCalArr2[iter3][iter4];		// This places the elements inside the array.
	
	}
/*
	This whole section is a repetition of what was done for the first matrix, entering the elements 
	for the second matrix follows exactly the same principle and code (with ammendments) as the first matrix

*/
	cout << endl;
	cout << endl; 

	cout << "Second Matrix" << endl
		 << "------------" << endl;
	for(iter3 = 0; iter3 < ROW; iter3++)
	{
		cout << endl;

		for(iter4 = 0; iter4 < COLUMN; iter4++)
	
			cout << MatrixCalArr2[iter3][iter4];
	}

	
//	cout << MatrixCalArr1[iter1][iter2];



	char MatrixCal_Oper = 0;			
	cout << endl;
	cout << endl;
	cout << "Enter Operation: + * -" << endl;	// This is a user prompt
	cin >> MatrixCal_Oper;				// This is what actually takes in the user choice of operator
	cout << endl; 
	cout << endl;
	cout << "Your Sum is"  << endl;
	cout <<"-------------" << endl;
		            

	/*
		To display the matrices like a sum I have to use the same method as 
		above using the for loops 

		for(iter3 = 0; iter3 < ROW; iter3++)
	{
		cout << endl;

		for(iter4 = 0; iter4 < COLUMN; iter4++)
	
			cout << MatrixCalArr2[iter3][iter4];
	}

		This should display on the console, the two 
		matrices entered and the operator choice, like a sum.
	*/

	for(iter1 = 0; iter1 < ROW; iter1++)										
	{
		cout << endl;

		for(iter2 = 0; iter2 < COLUMN; iter2++)

			
			cout << MatrixCalArr1[iter1][iter2];
	} 
	cout << endl;
	cout << endl;
	cout << MatrixCal_Oper;
	cout << endl;
	for(iter3 = 0; iter3 < ROW; iter3++)
	{
		cout << endl;

		for(iter4 = 0; iter4 < COLUMN; iter4++)
	
			cout << MatrixCalArr2[iter3][iter4];
	} 

	cout << endl;

	/*

		Part 3 
		------

		Gonna see if a switch statement will work for the arthmetic operations of this calculator in the same way
		it worked for the four func calculator exercise.



	*/


/*
	// Just a Test


*/
	cout << endl;
	cout << endl;
	cout << MatrixCalArr2[0][2]+ MatrixCalArr2[0][1] << endl;
	//cout << MatrixCalArr2[1][3] << endl;



	while(true){}
    return 0;
}

I've looked online in other forums and I have done a few google searches, I saw something about The Gaussien Elimination but this seemed to apply to solving algebraic equations using matrices.

Another hunch is that I have to use a function of some sort.....

Sorry for the length of this post,

Thanks

[Silvermaul]

Did you take a look here? http://www.cplusplus.com/doc/tutorial/arrays/

[ExponentialP]

Hi thanks for the reply, I had a look through that article, is there anything specific I should be looking for from the article ??? Is it the part talking about using #DEFINE (A macro) to carry out the calculation ???