In the Matrix class called Matrix. cs:

- matrix is a 2D array of double

- Cols is a read-only property that returns the number of columns in the matrix

- Rows is a read-only property that returns the number of rows in the matrix

- Create an indexer for a matrix. Note that for a matrix you need this[int i, int j] for both dimensions.

- Matrix is a constructor the instantiates the matrix of desired size.

- Create add, subtract and multiply methods that perform their respective operation on two matrices, called A and B matrices, returning a C result matrix. Note that they are called as C = A. add(B);

- The colsEqual, rowsEqual and dimsEqual methods compare the number of columns, rows and dimensions between two matrices for equality. Note bool b = A. dimsEqual(B); returns true if the matrices have the same dimensions.

- Equals is an override method that compares two matrices for equality. They are equal if both are null, or both have the same numeric values in the same element positions.

- GetHashCode is an override method that is implemented as:

// Overrides the GetHashCode method

public override int GetHashCode()

{

// Use sum for hash code

return sum().GetHashCode(); // Note that double overrides this too

}

- sum calculates the sum of all elements in the matrix.

- makeId makes an n x n identity matrix.

- clone returns a copy of this matrix.

- copy accepts a matrix and copied its elements to this.

- populateRand populates this matrix with random doubles.

- populateOrd populates this matrix with sequential doubles from 1.0 in the first element to d in the last, as traversed by a nested loop.

- The operator methods overload the operators to work with matrices.