On right track?

bradleyc · 10-13-2005, 01:20 AM

Quote:

a. Create a class named Matrix2x2 having four floating point data members named n1, n2, n3, n4. The class's default constructor should provide data members with default values of 1 if no explicit user initialization is provided. Additionally, provide member functions for displaying an object's data values and for calculating the determinant (see below). Also provide the class with an overloaded operator function that is capa¬ble of multiplying two Matrix2x2 objects according to the following procedure:
example of Matrix2x2 : | n1 n2 |
| n3 n4 |

multiplication:
|n1 n2| |N1 N2| |n1N1 + n2N3 n1N2 + n2N4|
|n3 n4| x |N3 N4| = |n3N2 + n4N4 n3N2 + n4N4|

determinant of |n1 n2| = n1n4 – n3n2
|n3 n4|
b. Include the class in a working C++ program that tests each of the class's member functions.

Code:

#include <iostream.h>
#include <stdlib.h>
#include <conio.h>


class Matrix2x2
{
private:
float n1;
float n2;
float n3;
float n4;

public:
Matrix2x2(int = 1. int = 1, int = 1, int =1);
void calcDet();
Matrix2x2 operator*();

};

Matrix2x2::Matrix2x2(int nOne, int nTwo, int nThree, int nFour)
{
 n1 = nOne;
 n2 = nTwo;
 n3 = nThree;
 n4 = nFour;
}

void Matrix2x2::calcDet()
{



}

Matrix2x2 Matrix2x2::operator*()
{


}

redhead · 10-13-2005, 04:35 AM

Quote:

Code:

#include <stdlib.h>

Waba.... where in this piece of code does it require the stdlib header ??

Quote:

Code:

#include <conio.h>

Given that this is just a simple implementation I would suggest to use the math header instead, atleast it is system independant, and later on we might end up doing some serius mathmatical equations where it might come in handy.

Quote:

Code:

Matrix2x2(int = 1. int = 1, int = 1, int =1);

That is just plain wrong
You can't create a function like that..

Code:

Matrix2x2(float nOne=1.0, float nTwo=1.0, float nThree=1.0, float nFour=1.0);

might be a better aproach, firstof you're private variables are floats, if you're gonna assign int values to them, why the hell declare them as floats in the first place??

Quote:

Code:

void calcDet();

You might want this to return a float, given that the determinant often reveals a value...

Quote:

Code:

Matrix2x2 operator*();

This could be returning Matrix2x2& if I'm not mistaken.

And the calculations for determinant and multiplications are strait out of the box, it's math 101. May I suggest Linear Algebra - Gateway to methmatics by Robert Messer, isbn: 0-06-501728-5 as a good reference.

Valmont · 10-13-2005, 10:42 AM

... and "we" don't like conio's in this part of the forum as well...

.

redhead · 10-13-2005, 01:43 PM

Hey Val, haven't seen you in a while..
Are you getting settled in ?