Calculator-for-Matrix-and-Algebra/nessesary/matrix.py

class Matrix:
    """
    We will write matrix in form of nd-array 

    Example:
    - [[1, 2], [3, 4]] is a 2x2 Matrix (row x column)
    - [[1, 2]] is 1x2 Matrix
    """
    
    def __init__(self, array: list):
        self.array = array
        self.row = len(array)
        self.column = len(array[0])
        
    def __add__(self, other):
        """
        Add matrix up and those matrix need same dimesional.
        >>> m1 = Matrix([[1, 2], [3, 4]])
        >>> m2 = Matrix([[1, 2], [3, 4]])
        >>> m3 = m1 + m2
        >>> m3.array
        [[2, 4], [6, 8]]
        """

        if (self.row != other.row) and (self.column != other.column):
            raise ValueError("Need matrix with same dimesional when add matrix up.")
        for row_index in range(self.row):
            for column_index in range(self.column):
                self.array[row_index][column_index] += other.array[row_index][column_index]
        return self

    def __sub__(self, other):
        """
        Substract matrix up and those matrix need same dimesional.
        >>> m1 = Matrix([[1, 2], [3, 4]])
        >>> m2 = Matrix([[1, 2], [3, 4]])
        >>> m3 = m1 - m2
        >>> m3.array
        [[0, 0], [0, 0]]
        """

        if (self.row != other.row) and (self.column != other.column):
            raise ValueError("Need matrix with same dimesional when add matrix up.")
        for row_index in range(self.row):
            for column_index in range(self.column):
                self.array[row_index][column_index] -= other.array[row_index][column_index]
        return self

    def __mul__(self, other):
        """
        Multiply matrix up and those matrix need same dimesional.
        >>> m1 = Matrix([[1, 2], [3, 4]])
        >>> m2 = Matrix([[1, 2], [3, 4]])
        >>> m3 = m1 * m2
        >>> m3.array
        [[7, 10], [15, 22]]
        >>> m1 = Matrix([[1, 2], [3, 4]])
        >>> m2 = 2
        >>> m4 = m1 * m2
        >>> m4.array
        [[2, 4], [6, 8]]
        """
        if isinstance(other, int) or isinstance(other, float):
            for row in range(self.row):
                for col in range(self.column):
                    self.array[row][col] = self.array[row][col] * other
            return self
        else:
            if  self.column == other.row:
                new_matrix = Matrix([[0 for i in range(other.column)] for k in range(self.row)])
                for row_index in range(self.row): 
                    for col_index in range(self.column):
                        for k in range(other.row):
                            new_matrix.array[row_index][col_index] += self.array[row_index][k] * other.array[k][col_index]
                return new_matrix
            else:
                raise ValueError("Can't multiply these matrix")

    def copy_matrix(self):
        """
        >>> m = Matrix([[1,2]])
        >>> m2 = m.copy_matrix()
        >>> m2 is m
        False
        """
        arr = self.array
        new_matrix = Matrix(arr)
        return new_matrix

    def new_matrix(a,i):#FUNCTION TO FIND THE NEW MATRIX
        arr = a.copy_matrix() 
        if len(arr) == 2:
            
            return arr
        else:
            arr.pop(0)
            for j in arr:
                j.pop(i)
                
            return arr

    def determinant(self):
        """
        Using Cofactor Expanion.
        |M| = sum[M(1,i)*Cofactor(M(1,i)) from i = 1 to n]

        Find determinant of Square Matrix
        >>> m1 = Matrix([[1,2,3],[1,2,3],[1,2,3]])
        >>> m1.determinant()
        0
        >>> m2 = Matrix([[13212,1,3,8321],[27,2,4,6],[321,5,2,-14],[312,21,211,3]])
        >>> m2.determinant()
        858575226
        """
        if self.row != self.column:
            raise ValueError(f"Can't Find determinant of {self.row} x {self.column} Matrix")

        if len(self.array) == 2 and len(self.array[0]) == 2:
            return self.array[0][0] * self.array[1][1] - self.array[1][0] * self.array[0][1]

        det = 0
        for col in range(len(self.array)):
            temp = self.copy_matrix()
            minor = lambda i, j : [row[:j] + row[j+1:] for row in (temp.array[:i]+temp.array[i+1:])]
            temp.array = minor(0,col)
            det += ((-1)**col)*self.array[0][col]*temp.determinant()
        return det

    def tranpose(self):
        """
        Substract matrix up and those matrix need same dimesional.
        >>> m1 = Matrix([[1, 2, 3], [3, 4, 5]])
        >>> m1 = m1.tranpose()
        >>> m1.array
        [[1, 3], [2, 4], [3, 5]]
        """
        new_matrix = Matrix([[0 for i in range(self.row)] for k in range(self.column)])
        for row_index in range(self.row):
            for col_index in range(self.column):
                new_matrix.array[col_index][row_index] += self.array[row_index][col_index]
        return new_matrix

    def inverse(self):
        det = self.determinant()
        pass

    def __str__(self):
       return f'Matrix({self.array})'

if __name__ == "__main__":
    import doctest
    doctest.testmod()
    # Use the following line INSTEAD if you want to print all tests anyway.
    # doctest.testmod(verbose = True)