Help with Classes and Arrays(Math Matrix)

root_beer · 09-30-2005, 06:05 PM

I have this assignment and its kicking the crap out of me. I have to have a program that has a math matrix. First it creates an identity matrix and prints it out to the console. After that it needs to add two matrices, subtract two matrices, and then multiply two matrices. I have the header file with all the functions and also the main.cpp file.

HEADER FILE

PHP Code:


			
#ifndef _MATRIX3_H_

#define _MATRIX3_H_





class Matrix3

{

private: 

    float values[3][3];



public:

    Matrix3(float v=1.0f); // Initialize diagonal to some value, default to 1.0



    Matrix3(float v11,float v12,float v13,

    float v21,float v22,float v23,

    float v31,float v32,float v33);



    void Identity(); // Create an identity matrix



    void SetValue(short row,short column,float v); // 0 based index

    float GetValue(short row,short column); // 0 based index



    Matrix3 Add(Matrix3 &);

    Matrix3 Subtract(Matrix3 &);

    Matrix3 Multiply(Matrix3 &);



    void Print(ostream &); // Print the matrix nicely to the console

};



#endif

MAIN.CPP

PHP Code:


			
Matrix3 mTest;

Matrix3 mAdd(2.0f);

Matrix3 mSubtract(3.0f);

Matrix3 mMultiply(4.0f);

Matrix3 mResult;



    //

    // Default matrix should have a 1.0 for the diagonal

    cout << "Default Matrix..." << endl;

    mTest.Print(cout);

    cout << endl;



    //

    // Add a couple of matrices

    cout << "Adding two matrices..." << endl;

    mResult=mAdd.Add(mTest);

    mResult.Print(cout);

    cout << endl;



    //

    // Subtract a couple of matrices

    cout << "Subtracting two matrices..." << endl;

    mResult=mSubtract.Subtract(mTest);

    mResult.Print(cout);

    cout << endl;



    //

    // Multiply a couple of matrices

    cout << "Multiplying two matrices..." << endl;

    mResult=mMultiply.Multiply(mAdd);

    mResult.Print(cout);

    cout << endl;



return 0;

}

I am completely lost. I have to use these exact functions and i just keep staring at it all and cant seem to piece it all together. If anyone can give me any tips that would be great. I am not looking for someone to just write out all the code, but just help on how it all goes together and that sort of thing.

Thanks in advance.

09-30-2005, 06:05 PM	#1 (permalink)
root_beer Registered User Join Date: Sep 2005 Posts: 2 OS: XP	Help with Classes and Arrays(Math Matrix) I have this assignment and its kicking the crap out of me. I have to have a program that has a math matrix. First it creates an identity matrix and prints it out to the console. After that it needs to add two matrices, subtract two matrices, and then multiply two matrices. I have the header file with all the functions and also the main.cpp file. HEADER FILE PHP Code: #ifndef _MATRIX3_H_ #define _MATRIX3_H_ class Matrix3 { private: float values[3][3]; public: Matrix3(float v=1.0f); // Initialize diagonal to some value, default to 1.0 Matrix3(float v11,float v12,float v13, float v21,float v22,float v23, float v31,float v32,float v33); void Identity(); // Create an identity matrix void SetValue(short row,short column,float v); // 0 based index float GetValue(short row,short column); // 0 based index Matrix3 Add(Matrix3 &); Matrix3 Subtract(Matrix3 &); Matrix3 Multiply(Matrix3 &); void Print(ostream &); // Print the matrix nicely to the console }; #endif MAIN.CPP PHP Code: Matrix3 mTest; Matrix3 mAdd(2.0f); Matrix3 mSubtract(3.0f); Matrix3 mMultiply(4.0f); Matrix3 mResult; // // Default matrix should have a 1.0 for the diagonal cout << "Default Matrix..." << endl; mTest.Print(cout); cout << endl; // // Add a couple of matrices cout << "Adding two matrices..." << endl; mResult=mAdd.Add(mTest); mResult.Print(cout); cout << endl; // // Subtract a couple of matrices cout << "Subtracting two matrices..." << endl; mResult=mSubtract.Subtract(mTest); mResult.Print(cout); cout << endl; // // Multiply a couple of matrices cout << "Multiplying two matrices..." << endl; mResult=mMultiply.Multiply(mAdd); mResult.Print(cout); cout << endl; return 0; } I am completely lost. I have to use these exact functions and i just keep staring at it all and cant seem to piece it all together. If anyone can give me any tips that would be great. I am not looking for someone to just write out all the code, but just help on how it all goes together and that sort of thing. Thanks in advance.