s21_matrix+

Implementation of the s21_matrix_oop.h library. Study project.

The russian version of the task can be found in the repository.

Implementation of basic operations with matrices: comparison, addition, subtraction, multiplication, multiplication by number, transpose, calculation of determinant, calculation of matrix of algebraic complements, finding inverse of the matrix.

• The program is developed in C++ language of C++17 standard using gcc compiler;
• The program code is located in the src folder;
• The code of the program is written in accordance with Google style;
• Implemented: S21Matrix class, default constructor, parametrized constructor, copy and move constructors, assignment and compare operators overload, destructor, accessors and mutators.
• Full coverage of class methods is provided with unit-tests using the GTest library;
• Makefile with targets clean, check_style, s21_matrix_oop.a, test, gcov_report is provided.

Class s21Matrix

class S21Matrix {
    private:
        // Attributes
        int rows_, cols_;         // Rows and columns
        double **matrix_;         // Pointer to the memory where the matrix is allocated

    public:
        S21Matrix();              // Default constructor
        ~S21Matrix();             // Destructor

        // Other methods..
}

You can get the desired element using indices as follows A(1,1) = 1, where the first index is the row number, the second is the column number.

The order of a matrix is the number of its rows or columns.
The main diagonal of a square matrix is the diagonal from the upper left to the lower right corner.

A rectangular matrix (B) is a matrix with the number of rows not equal to the number of columns.
A square matrix (A) is a matrix with the number of rows equal to the number of columns.

Matrix operations

Below is a brief description of the S21Matrix class methods.

Constructors and destructors:

Method	Description
S21Matrix()	A basic constructor that initialises a matrix of some predefined dimension.
S21Matrix(int rows, int cols)	Parametrized constructor with number of rows and columns.
S21Matrix(const S21Matrix& other)	Copy constructor.
S21Matrix(S21Matrix&& other)	Move constructor.
~S21Matrix()	Destructor.

Operators overload:

Operator	Description	Exceptional situations
+	Addition of two matrices.	Different matrix dimensions.
-	Subtraction of one matrix from another.	Different matrix dimensions.
*	Matrix multiplication and matrix multiplication by a number.	The number of columns of the first matrix does not equal the number of rows of the second matrix.
==	Checks for matrices equality (EqMatrix).
=	Assignment of values from one matrix to another one.
+=	Addition assignment (SumMatrix)	different matrix dimensions.
-=	Difference assignment (SubMatrix)	different matrix dimensions.
*=	Multiplication assignment (MulMatrix/MulNumber).	The number of columns of the first matrix does not equal the number of rows of the second matrix.
(int i, int j)	Indexation by matrix elements (row, column).	Index is outside the matrix.

Class methods:

Operation	Description	Exceptional situations
bool EqMatrix(const S21Matrix& other)	Checks matrices for equality with each other.
void SumMatrix(const S21Matrix& other)	Adds the second matrix to the current one	different matrix dimensions.
void SubMatrix(const S21Matrix& other)	Subtracts another matrix from the current one	different matrix dimensions.
void MulNumber(const double num)	Multiplies the current matrix by a number.
void MulMatrix(const S21Matrix& other)	Multiplies the current matrix by the second matrix.	The number of columns of the first matrix is not equal to the number of rows of the second matrix.
S21Matrix Transpose()	Creates a new transposed matrix from the current one and returns it.
S21Matrix CalcComplements()	Calculates the algebraic addition matrix of the current one and returns it.	The matrix is not square.
double Determinant()	Calculates and returns the determinant of the current matrix.	The matrix is not square.
S21Matrix InverseMatrix()	Calculates and returns the inverse matrix.	Matrix determinant is 0.