Bugfixes

Update tests
Add javadoc comments

src/main/java/com/mattrixwv/matrix/ModMatrix.java

@@ -1,20 +1,35 @@
 //Matrix/src/main/java/com/mattrixwv/matrix/ModMatrix.java
 //Mattrixwv
 // Created: 02-09-22
-//Modified: 07-01-22
+//Modified: 08-11-24
 package com.mattrixwv.matrix;
 
 
 import java.util.Arrays;
 
+import com.mattrixwv.matrix.exceptions.InvalidCoordinatesException;
 import com.mattrixwv.matrix.exceptions.InvalidGeometryException;
+import com.mattrixwv.matrix.exceptions.InvalidRowSizeException;
 import com.mattrixwv.matrix.exceptions.InvalidScalarException;
+import com.mattrixwv.matrix.exceptions.NullMatrixException;
 
 
+/**
+ * Represents a matrix of integers that have been run through a modulus function, and provides various matrix operations.
+ */
 public class ModMatrix extends IntegerMatrix{
+	/**
+	 * The mod used on each element of the matrix
+	 */
 	protected int mod;
 
-	//Helper functions
+	//?Helper functions
+	/**
+	 * Set the mod values
+	 *
+	 * @param mod The new mod value
+	 * @throws InvalidScalarException If the mod value is less than or equal to 0
+	 */
 	protected void setMod(int mod){
 		if(mod <= 0){
 			throw new InvalidScalarException("The mod must be > 0");
@@ -22,6 +37,12 @@ public class ModMatrix extends IntegerMatrix{
 
 		this.mod = mod;
 	}
+	/**
+	 * Get the mod value of a number
+	 *
+	 * @param value The value to mod
+	 * @return The modded value
+	 */
 	protected int modValue(int value){
 		int newValue = value % mod;
 
@@ -31,9 +52,16 @@ public class ModMatrix extends IntegerMatrix{
 
 		return newValue;
 	}
+	/**
+	 * Get the mod value of each element in an array
+	 *
+	 * @param values The array of values
+	 * @return The array of modded values
+	 * @throws NullMatrixException If the array is null
+	 */
 	protected int[] modValues(int[] values){
 		if(values == null){
-			throw new InvalidGeometryException("Array cannot be null");
+			throw new NullMatrixException("Array cannot be null");
 		}
 
 		int[] newValues = new int[values.length];
@@ -44,6 +72,9 @@ public class ModMatrix extends IntegerMatrix{
 
 		return newValues;
 	}
+	/**
+	 * Get the mod value of each element in the matrix
+	 */
 	protected void modGrid(){
 		for(int row = 0;row < getNumRows();++row){
 			for(int col = 0;col < getNumCols();++col){
@@ -51,161 +82,440 @@ public class ModMatrix extends IntegerMatrix{
 			}
 		}
 	}
+	/**
+	 * Sets the matrix grid to the specified 2D array. Validates the input to ensure
+	 * all rows are of equal length.
+	 *
+	 * @param grid The 2D array to set as the matrix grid.
+	 * @throws InvalidRowSizeException If the rows of the matrix are not all the same length.
+	 */
 	@Override
 	protected void setGrid(int[][] grid){
 		super.setGrid(grid);
 		modGrid();
 	}
 
-	//Constructors
+	//?Constructors
+	/**
+	 * Constructs an empty matrix (0x0).
+	 *
+	 * @param mod The mod value to use.
+	 */
 	public ModMatrix(int mod){
 		super();
 		setMod(mod);
 		modGrid();
 	}
+	/**
+	 * Constructs a matrix with the specified grid.
+	 *
+	 * @param grid The 2D array to initialize the matrix with.
+	 * @param mod The mod value to use.
+	 */
 	public ModMatrix(int[][] grid, int mod){
 		super();
 		setMod(mod);
 		setGrid(grid);
 	}
+	/**
+	 * Constructs a copy of the specified matrix.
+	 *
+	 * @param matrix The matrix to copy.
+	 */
 	public ModMatrix(ModMatrix matrix){
 		super();
 		setMod(matrix.mod);
 		setGrid(matrix.grid);
 	}
+	/**
+	 * Constructs a ModMatrix based on the given IntegerMatrix
+	 *
+	 * @param matrix The matrix to copy.
+	 * @param mod The mod value to use.
+	 */
 	public ModMatrix(IntegerMatrix matrix, int mod){
 		super();
 		setMod(mod);
 		setGrid(matrix.grid);
 	}
+	/**
+	 * Constructs a matrix with the specified number of rows and columns, filled with the specified value.
+	 *
+	 * @param rows The number of rows.
+	 * @param cols The number of columns.
+	 * @param fill The value to fill the matrix with.
+	 * @param mod The mod value to use.
+	 * @throws InvalidGeometryException If the number of rows or columns is less than or equal to zero.
+	 */
 	public ModMatrix(int rows, int cols, int fill, int mod){
 		super(rows, cols, fill);
 		setMod(mod);
 		modGrid();
 	}
 
-	//Gets
+	//?Gets
+	/**
+	 * Get the mod value of the matrix
+	 *
+	 * @return The mod value
+	 */
 	public int getMod(){
 		return mod;
 	}
+	/**
+	 * Returns a new matrix that is a copy of the specified row.
+	 *
+	 * @param row The index of the row to retrieve.
+	 * @return A new ModMatrix instance containing the specified row.
+	 * @throws InvalidCoordinatesException If the row index is out of bounds.
+	 */
 	@Override
 	public ModMatrix getRow(int row){
 		return new ModMatrix(super.getRow(row), mod);
 	}
+	/**
+	 * Returns the number of rows in the matrix.
+	 *
+	 * @return The number of rows.
+	 */
 	@Override
 	public ModMatrix getCol(int col){
 		return new ModMatrix(super.getCol(col), mod);
 	}
-	//Sets
+
+	//?Sets
+	/**
+	 * Sets the value at the specified row and column.
+	 *
+	 * @param row   The row index.
+	 * @param col   The column index.
+	 * @param value The value to set.
+	 * @throws InvalidCoordinatesException If the row or column index is out of bounds.
+	 */
 	@Override
 	public void set(int row, int col, int value){
 		super.set(row, col, modValue(value));
 	}
+	/**
+	 * Sets the specified row with the given array of elements.
+	 *
+	 * @param row	 The row index.
+	 * @param elements The array of elements to set.
+	 * @throws InvalidCoordinatesException If the row index is out of bounds.
+	 * @throws InvalidGeometryException	 If the length of the elements array does not match the number of columns.
+	 */
 	@Override
 	public void setRow(int row, int[] elements){
 		super.setRow(row, modValues(elements));
 	}
+	/**
+	 * Sets the specified row with the given matrix containing a single row.
+	 * Converts the IntegerMatrix to a ModMatrix before the operation.
+	 *
+	 * @param row	 The row index.
+	 * @param matrix  The matrix containing a single row to set.
+	 * @throws NullMatrixException		   If the matrix is null.
+	 * @throws InvalidGeometryException	  If the matrix does not contain a single row.
+	 */
 	@Override
 	public void setRow(int row, IntegerMatrix matrix){
-		setRow(row, new ModMatrix(matrix, Integer.MAX_VALUE));
+		setRow(row, new ModMatrix(matrix, mod));
 	}
+	/**
+	 * Sets the specified row with the given matrix containing a single row.
+	 *
+	 * @param row	 The row index.
+	 * @param matrix  The matrix containing a single row to set.
+	 * @throws NullMatrixException		   If the matrix is null.
+	 * @throws InvalidGeometryException	  If the matrix does not contain a single row.
+	 */
 	public void setRow(int row, ModMatrix matrix){
 		super.setRow(row, matrix);
 		modGrid();
 	}
+	/**
+	 * Sets the specified column with the given array of elements.
+	 *
+	 * @param col	 The column index.
+	 * @param elements The array of elements to set.
+	 * @throws InvalidCoordinatesException If the column index is out of bounds.
+	 * @throws InvalidGeometryException	 If the length of the elements array does not match the number of rows.
+	 */
 	@Override
 	public void setCol(int col, int[] elements){
 		super.setCol(col, elements);
 		modGrid();
 	}
+	/**
+	 * Sets the specified column with the given matrix containing a single column.
+	 * Converts the IntegerMatrix to a ModMatrix before the operation.
+	 *
+	 * @param col	 The column index.
+	 * @param matrix  The matrix containing a single column to set.
+	 * @throws NullMatrixException		   If the matrix is null.
+	 * @throws InvalidGeometryException	  If the matrix does not contain a single column.
+	 */
 	@Override
 	public void setCol(int col, IntegerMatrix matrix){
-		setCol(col, new ModMatrix(matrix, Integer.MAX_VALUE));
+		setCol(col, new ModMatrix(matrix, mod));
 	}
+	/**
+	 * Sets the specified column with the given matrix containing a single column.
+	 *
+	 * @param col	 The column index.
+	 * @param matrix  The matrix containing a single column to set.
+	 * @throws NullMatrixException		   If the matrix is null.
+	 * @throws InvalidGeometryException	  If the matrix does not contain a single column.
+	 */
 	public void setCol(int col, ModMatrix matrix){
 		super.setCol(col, matrix);
 		modGrid();
 	}
-	//Adds
+
+	//?Adds
+	/**
+	 * Adds a new row with the specified array of elements to the matrix.
+	 *
+	 * @param elements The array of elements to add as a new row.
+	 * @throws NullMatrixException		   If the elements array is null.
+	 * @throws InvalidGeometryException	  If the length of the elements array does not match the number of columns.
+	 */
 	@Override
 	public void addRow(int[] elements){
 		super.addRow(modValues(elements));
 	}
+	/**
+	 * Adds a new row with the given matrix containing a single row to the matrix.
+	 * Converts the IntegerMatrix to a ModMatrix before the operation.
+	 *
+	 * @param matrix The matrix containing a single row to add.
+	 * @throws NullMatrixException		   If the matrix is null.
+	 * @throws InvalidGeometryException	  If the matrix does not contain a single row.
+	 */
 	@Override
 	public void addRow(IntegerMatrix matrix){
-		addRow(new ModMatrix(matrix, Integer.MAX_VALUE));
+		addRow(new ModMatrix(matrix, mod));
 	}
+	/**
+	 * Adds a new row with the given matrix containing a single row to the matrix.
+	 *
+	 * @param matrix The matrix containing a single row to add.
+	 * @throws NullMatrixException		   If the matrix is null.
+	 * @throws InvalidGeometryException	  If the matrix does not contain a single row.
+	 */
 	public void addRow(ModMatrix matrix){
 		super.addRow(matrix);
 		modGrid();
 	}
+	/**
+	 * Adds a new column with the specified array of elements to the matrix.
+	 *
+	 * @param elements The array of elements to add as a new column.
+	 * @throws NullMatrixException		   If the elements array is null.
+	 * @throws InvalidGeometryException	  If the length of the elements array does not match the number of rows.
+	 */
 	@Override
 	public void addCol(int[] elements){
 		super.addCol(modValues(elements));
 	}
+	/**
+	 * Adds a new column with the given matrix containing a single column to the matrix.
+	 * Converts the IntegerMatrix to a ModMatrix before the operation.
+	 *
+	 * @param matrix The matrix containing a single column to add.
+	 * @throws NullMatrixException		   If the matrix is null.
+	 * @throws InvalidGeometryException	  If the matrix does not contain a single column.
+	 */
 	@Override
 	public void addCol(IntegerMatrix matrix){
-		addCol(new ModMatrix(matrix, Integer.MAX_VALUE));
+		addCol(new ModMatrix(matrix, mod));
 	}
+	/**
+	 * Adds a new column with the given matrix containing a single column to the matrix.
+	 *
+	 * @param matrix The matrix containing a single column to add.
+	 * @throws NullMatrixException		   If the matrix is null.
+	 * @throws InvalidGeometryException	  If the matrix does not contain a single column.
+	 */
 	public void addCol(ModMatrix matrix){
 		super.addCol(matrix);
 		modGrid();
 	}
+	/**
+	 * Appends the specified matrix to the right side of the current matrix.
+	 * Converts the IntegerMatrix to a ModMatrix before the operation.
+	 *
+	 * @param rightSide The matrix to append to the right side.
+	 * @return A new ModMatrix instance with the right-side matrix appended.
+	 * @throws NullMatrixException		   If the right-side matrix is null.
+	 * @throws InvalidGeometryException	  If the number of rows does not match.
+	 */
 	@Override
 	public ModMatrix appendRight(IntegerMatrix rightSide){
-		return appendRight(new ModMatrix(rightSide, Integer.MAX_VALUE));
+		return appendRight(new ModMatrix(rightSide, mod));
 	}
+	/**
+	 * Appends the specified matrix to the right side of the current matrix.
+	 *
+	 * @param rightSide The matrix to append to the right side.
+	 * @return A new ModMatrix instance with the right-side matrix appended.
+	 * @throws NullMatrixException		   If the right-side matrix is null.
+	 * @throws InvalidGeometryException	  If the number of rows does not match.
+	 */
 	public ModMatrix appendRight(ModMatrix rightSide){
 		return new ModMatrix(super.appendRight(rightSide), mod);
 	}
+	/**
+	 * Appends the specified matrix to the bottom of the current matrix.
+	 * Converts the IntegerMatrix to a ModMatrix before the operation.
+	 *
+	 * @param bottomSide The matrix to append to the bottom.
+	 * @return A new ModMatrix instance with the bottom matrix appended.
+	 * @throws NullMatrixException		   If the bottom matrix is null.
+	 * @throws InvalidGeometryException	  If the number of columns does not match.
+	 */
 	@Override
-	public ModMatrix appendBottom(IntegerMatrix rightSide){
-		return appendBottom(new ModMatrix(rightSide, Integer.MAX_VALUE));
+	public ModMatrix appendBottom(IntegerMatrix bottomSide){
+		return appendBottom(new ModMatrix(bottomSide, mod));
 	}
-	public ModMatrix appendBottom(ModMatrix rightSide){
-		return new ModMatrix(super.appendBottom(rightSide), mod);
+	/**
+	 * Appends the specified matrix to the bottom of the current matrix.
+	 *
+	 * @param bottomSide The matrix to append to the bottom.
+	 * @return A new ModMatrix instance with the bottom matrix appended.
+	 * @throws NullMatrixException		   If the bottom matrix is null.
+	 * @throws InvalidGeometryException	  If the number of columns does not match.
+	 */
+	public ModMatrix appendBottom(ModMatrix bottomSide){
+		return new ModMatrix(super.appendBottom(bottomSide), mod);
 	}
 
-	//Simple operations
+	//?Simple operations
+		/**
+	 * Generates an identity matrix of the given size.
+	 *
+	 * @param size The size of the identity matrix.
+	 * @return A new ModMatrix instance representing the identity matrix.
+	 * @throws InvalidGeometryException If the size is less than or equal to zero.
+	 */
 	public static ModMatrix generateIdentity(int size){
 		return generateIdentity(size, Integer.MAX_VALUE);
 	}
+		/**
+	 * Generates an identity matrix of the given size.
+	 *
+	 * @param size The size of the identity matrix.
+	 * @param mod The mod value to use.
+	 * @return A new ModMatrix instance representing the identity matrix.
+	 * @throws InvalidGeometryException If the size is less than or equal to zero.
+	 */
 	public static ModMatrix generateIdentity(int size, int mod){
 		return new ModMatrix(IntegerMatrix.generateIdentity(size), mod);
 	}
+	/**
+	 * Adds the specified matrix to the current matrix.
+	 * Converts the IntegerMatrix to a ModMatrix before the operation.
+	 *
+	 * @param rightSide The matrix to add.
+	 * @return A new ModMatrix instance with the result of the addition.
+	 * @throws InvalidGeometryException If the matrices do not have the same dimensions.
+	 */
 	@Override
 	public ModMatrix add(IntegerMatrix rightSide){
-		return add(new ModMatrix(rightSide, Integer.MAX_VALUE));
+		return add(new ModMatrix(rightSide, mod));
 	}
+	/**
+	 * Adds the specified matrix to the current matrix.
+	 *
+	 * @param rightSide The matrix to add.
+	 * @return A new ModMatrix instance with the result of the addition.
+	 * @throws InvalidGeometryException If the matrices do not have the same dimensions.
+	 */
 	public ModMatrix add(ModMatrix rightSide){
 		return new ModMatrix(super.add(rightSide), mod);
 	}
+	/**
+	 * Adds the scalar to every element in the matrix.
+	 *
+	 * @param scalar The scalar to add.
+	 * @return A new ModMatrix instance with the result of the addition.
+	 */
 	@Override
 	public ModMatrix add(int scalar){
 		return new ModMatrix(super.add(scalar), mod);
 	}
+	/**
+	 * Subtracts the specified matrix from the current matrix.
+	 * Converts the IntegerMatrix to a ModMatrix before the operation.
+	 *
+	 * @param rightSide The matrix to subtract.
+	 * @return A new ModMatrix instance with the result of the subtraction.
+	 * @throws InvalidGeometryException If the matrices do not have the same dimensions.
+	 */
 	@Override
 	public ModMatrix subtract(IntegerMatrix rightSide){
-		return subtract(new ModMatrix(rightSide, Integer.MAX_VALUE));
+		return subtract(new ModMatrix(rightSide, mod));
 	}
+	/**
+	 * Subtracts the specified matrix from the current matrix.
+	 *
+	 * @param rightSide The matrix to subtract.
+	 * @return A new ModMatrix instance with the result of the subtraction.
+	 * @throws InvalidGeometryException If the matrices do not have the same dimensions.
+	 */
 	public ModMatrix subtract(ModMatrix rightSide){
 		return new ModMatrix(super.subtract(rightSide), mod);
 	}
+	/**
+	 * Subtracts the scalar from every element in the matrix.
+	 *
+	 * @param scalar The scalar to subtract.
+	 * @return A new ModMatrix instance with the result of the subtraction.
+	 */
 	@Override
 	public ModMatrix subtract(int scalar){
 		return new ModMatrix(super.subtract(scalar), mod);
 	}
+	/**
+	 * Multiplies the current matrix by the specified matrix.
+	 * Converts the IntegerMatrix to a ModMatrix before the operation.
+	 *
+	 * @param rightSide The matrix to multiply by.
+	 * @return A new ModMatrix instance with the result of the multiplication.
+	 * @throws InvalidGeometryException If the number of columns in the current matrix does not match the number of rows in the right-side matrix.
+	 */
 	@Override
-	public ModMatrix multiply(IntegerMatrix matrix){
-		return multiply(new ModMatrix(matrix, Integer.MAX_VALUE));
+	public ModMatrix multiply(IntegerMatrix rightSide){
+		return multiply(new ModMatrix(rightSide, mod));
 	}
-	public ModMatrix multiply(ModMatrix matrix){
-		return new ModMatrix(super.multiply(matrix), mod);
+	/**
+	 * Multiplies the current matrix by the specified matrix.
+	 *
+	 * @param rightSide The matrix to multiply by.
+	 * @return A new ModMatrix instance with the result of the multiplication.
+	 * @throws InvalidGeometryException If the number of columns in the current matrix does not match the number of rows in the right-side matrix.
+	 */
+	public ModMatrix multiply(ModMatrix rightSide){
+		return new ModMatrix(super.multiply(rightSide), mod);
 	}
+	/**
+	 * Multiplies every element in the matrix by the scalar.
+	 *
+	 * @param scalar the scalar to multiply
+	 * @return A new ModMatrix instance with the result of the multiplication
+	 */
 	@Override
 	public ModMatrix multiply(int scalar){
 		return new ModMatrix(super.multiply(scalar), mod);
 	}
+	/**
+	 * Multiplies the current matrix by itself the given number of times.
+	 *
+	 * @param power The number of times to multiply the matrix by itself
+	 * @return A new ModMatrix instance with the result of the multiplication
+	 * @throws InvalidScalarException If the power is negative
+	 * @throws InvalidGeometryException If the matrix is not square
+	 */
 	@Override
 	public ModMatrix pow(int power){
 		//Make sure the matrix is square so it can be multiplied
@@ -230,30 +540,82 @@ public class ModMatrix extends IntegerMatrix{
 		//Return the new grid
 		return newMatrix;
 	}
+	/**
+	 * Calculates the dot product of the two matrices.
+	 * Converts the IntegerMatrix to a ModMatrix before the operation.
+	 *
+	 * @param rightSide The matrix to use on the right side of the calculation
+	 * @return The dot product of the two matrices
+	 * @throws NullMatrixException If the right matrix is null
+	 * @throws InvalidGeometryException If the matrices do not have compatible dimensions
+	 */
 	@Override
 	public int dotProduct(IntegerMatrix rightSide){
-		return dotProduct(new ModMatrix(rightSide, Integer.MAX_VALUE));
+		return dotProduct(new ModMatrix(rightSide, mod));
 	}
+	/**
+	 * Calculates the dot product of the two matrices.
+	 *
+	 * @param rightSide The matrix to use on the right side of the calculation
+	 * @return The dot product of the two matrices
+	 * @throws NullMatrixException If the right matrix is null
+	 * @throws InvalidGeometryException If the matrices do not have compatible dimensions
+	 */
 	public int dotProduct(ModMatrix rightSide){
-		return super.dotProduct(rightSide);
+		return super.dotProduct(rightSide) % mod;
 	}
+	/**
+	 * Calculates the Hadamard product of the two matrices.
+	 * Converts the IntegerMatrix to a ModMatrix before the operation.
+	 *
+	 * @param rightSide The matrix to use on the right side of the calculation
+	 * @return The Hadamard product of the two matrices
+	 * @throws NullMatrixException If the right matrix is null
+	 * @throws InvalidGeometryException If the matrices do not have compatible dimensions
+	 */
 	@Override
 	public ModMatrix hadamardProduct(IntegerMatrix rightSide){
-		return hadamardProduct(new ModMatrix(rightSide, Integer.MAX_VALUE));
+		return hadamardProduct(new ModMatrix(rightSide, mod));
 	}
+	/**
+	 * Calculates the Hadamard product of the two matrices.
+	 *
+	 * @param rightSide The matrix to use on the right side of the calculation
+	 * @return The Hadamard product of the two matrices
+	 * @throws NullMatrixException If the right matrix is null
+	 * @throws InvalidGeometryException If the matrices do not have compatible dimensions
+	 */
 	public ModMatrix hadamardProduct(ModMatrix rightSide){
 		return new ModMatrix(super.hadamardProduct(rightSide), mod);
 	}
 
-	//Complex operations
+	//?Complex operations
+	/**
+	 * Transposes the current matrix (i.e., swaps rows and columns).
+	 *
+	 * @return A new ModMatrix instance representing the transposed matrix.
+	 */
 	@Override
 	public ModMatrix transpose(){
 		return new ModMatrix(super.transpose(), mod);
 	}
+	/**
+	 * Calculates the cofactor matrix of the current matrix.
+	 *
+	 * @return A new ModMatrix instance representing the cofactor matrix.
+	 * @throws InvalidGeometryException If the matrix is not square.
+	 * @see #cofactor()
+	 */
 	@Override
 	public ModMatrix cof(){
 		return cofactor();
 	}
+	/**
+	 * Calculates the cofactor matrix of the current matrix.
+	 *
+	 * @return A new ModMatrix instance representing the cofactor matrix.
+	 * @throws InvalidGeometryException If the matrix is not square.
+	 */
 	@Override
 	public ModMatrix cofactor(){
 		//Make sure the matrix is square
@@ -281,14 +643,33 @@ public class ModMatrix extends IntegerMatrix{
 		//Return the new matrix
 		return new ModMatrix(newGrid, mod);
 	}
+	/**
+	 * Calculates the adjoint matrix of the current matrix.
+	 *
+	 * @return A new ModMatrix instance representing the adjoint matrix.
+	 * @throws InvalidGeometryException If the matrix is not square.
+	 * @see #adjoint()
+	 */
 	@Override
 	public ModMatrix adj(){
 		return adjoint();
 	}
+	/**
+	 * Calculates the adjoint matrix of the current matrix.
+	 *
+	 * @return A new ModMatrix instance representing the adjoint matrix.
+	 * @throws InvalidGeometryException If the matrix is not square.
+	 */
 	@Override
 	public ModMatrix adjoint(){
 		return cofactor().transpose();
 	}
+	/**
+	 * Calculates the inverse of the current matrix.
+	 *
+	 * @return A new ModMatrix instance representing the inverse matrix.
+	 * @throws InvalidGeometryException If the matrix is not square or if the determinant is 0.
+	 */
 	@Override
 	public ModMatrix inverse(){
 		//Make sure the matrix is square
@@ -317,7 +698,15 @@ public class ModMatrix extends IntegerMatrix{
 		return adjoint().multiply(determinantInverse);
 	}
 
-	//Object functions
+	//?Object functions
+	/**
+	 * Determines whether the given object is equal to the current matrix.
+	 * Can determine equality using ModMatrix or int[][].
+	 *
+	 * @param rightSide The object to compare to the current matrix.
+	 * @return True if the objects are equal, false otherwise.
+	 * @see #equals(ModMatrix)
+	 */
 	@Override
 	public boolean equals(Object rightSide){
 		if(rightSide == null){
@@ -335,7 +724,17 @@ public class ModMatrix extends IntegerMatrix{
 			return false;
 		}
 	}
+	/**
+	 * Determines whether the given ModMatrix is equal to the current matrix.
+	 *
+	 * @param rightMatrix The ModMatrix to compare to the current matrix.
+	 * @return True if the matrices are equal, false otherwise.
+	 */
 	public boolean equals(ModMatrix rightMatrix){
+		if(rightMatrix == null){
+			return false;
+		}
+
 		//Make sure they have the same number of elements
 		if((getNumRows() != rightMatrix.getNumRows()) || (getNumCols() != rightMatrix.getNumCols())){
 			return false;
@@ -353,10 +752,20 @@ public class ModMatrix extends IntegerMatrix{
 		//If false hasn't been return yet then they are equal
 		return true;
 	}
+	/**
+	 * Calculates a hash code for the current matrix.
+	 *
+	 * @return The hash code for the current matrix.
+	 */
 	@Override
 	public int hashCode(){
 		return Arrays.hashCode(grid);
 	}
+	/**
+	 * Returns a string representation of the matrix, with rows and columns formatted for readability.
+	 *
+	 * @return A string representation of the matrix.
+	 */
 	@Override
 	public String toString(){
 		return super.toString() + "\nmod(" + mod + ")";