public class Matrix

{

private int nRow, nCol;

private double[] data; // must store as linear array unless 0

//getter for NRow - do not modify

public int getNRow()

{

return nRow;

}

//getter for NCol - do not modify

public int getNCol()

{

return nCol;

}

/**

* set nRow to r if r is not negative, otherwise set nRow to 0

* @param r: value to be assigned to nRow

*/

public void setNRow(int r)

{

if(r < 0)

nRow = 0;

else

nRow = r;//to be completed

}

/**

* set nCol to c if c is not negative, otherwise set nCol to 0

* @param c: value to be assigned to nCol

*/

public void setNCol(int c)

{

if(c < 0)

nCol = 0;

else

nCol = c;//to be completed

}

/**

*

* @return true if both nRow and nCol are zero, false otherwise

*/

public boolean isEmpty()

{

if(nRow == 0 && nCol ==0)

return true;

else

return false; //to be completed

}

/**

* DO NOT MODIFY

* if arr is null, instance array data should become null,

* otherwise if arr.length is not equal to nRow * nCol,

* set nRow, nCol to 0 and data to null,

* otherwise instantiate instance array data to be of the

* same size as arr. then copy each item of arr into data.

* IMPORTANT: do not re-declare data!

*

* @param arr

*/

public void setData(double[] arr) {

if(arr == null)

data = null;

else {

if(nRow*nCol != arr.length) {

nRow = 0;

nCol = 0;

data = null;

return;

}

data = new double[arr.length];

for(int i=0; i < arr.length; i++) {

data[i] = arr[i];

}

}

}

/**

* Default constructor.

* instance variables nRow and nCol should be set to 0 using the setters.

* the data member data should be set to null

*/

public Matrix()

{

setNRow(0);

setNCol(0);

data = null;//to be completed

}

/**

* Constructor a matrix which has r rows and c columns.

* data member nRow and nCol should be set accordingly using setters.

* AFTER THAT, instance array data should be instantiated to size nRow*nCol

* @param r: number of rows

* @param c: number of columns

*/

public Matrix(int r, int c)

{

setNRow(r);

setNCol(c);

data = new double [r*c];//to be completed

}

/**

*

* @return true if the matrix is a square matrix (a matrix

* for which number of rows and number of columns is the same)

*/

public boolean isSquare() {

if(data.length == nCol * nRow)

return true;

else

return false; //to be completed

}

/**

*

* @param other

* @return true if calling object and parameter object have the same

* dimensions (they both have the same number of rows compared to each

* other, and the same number of columns compared to each other), false otherwise

*/

public boolean sameDimensions(Matrix other)

{

if(nRow == other.nRow)

if(nCol == other.nCol)

return true;

return false; //to be completed

}

/**

* @param r

* @return true if r is a valid row number, false otherwise

* only row numbers 0 to nRow-1 (inclusive on both sides) are valid

*/

public boolean isValidRowNumber(int r) {

if(r >= 0 && r

return true;

}

return false; //to be completed

}

/**

* @param c

* @return true if c is a valid column number, false otherwise

* only column numbers 0 to nCol-1 (inclusive on both sides) are valid

*/

public boolean isValidColumnNumber(int c) {

if(c >= 0 && c

return true;

}

return false; //to be completed

}

/**

* The constructor must first check that r * c is equal to the length of array d.

* if this requirement does not meet, member nRow and nCol should be set to 0 and

* data should be set to null.

* if the requirement is met, nRow should be set to r and nCol should be set to c.

* d should be copied into data using setData(double[] arr) method

* @param r: number of rows

* @param c: number of columns

* @param d: array d to populate data

*/

public Matrix(int r, int c, double[] d)

{

//to be completed

}

/**

* The method must check that r and c are valid row numbers and column numbers

* respectively. Note that row and column numbers begin with 0.

* It should return 0 if r or c is out of range of the dimension of the matrix

* @param r

* @param c

* @return an element of the Matrix at row r and column c

*/

public double get(int r, int c)

{

return 0; //to be completed

}

/**

* The method must check that r and c are valid row numbers and column numbers

* respectively. Note that row and column numbers begin with 0.

* It should return 0 if r or c is out of range of the dimension of the matrix

* @param r

* @param c

* @return an element of the Matrix at row r and column c

*/

public double get(int r, int c)

{

return 0; //to be completed

}