> java MatrixTester 92 First 7 rows/columns of a: 72.6 85.5 81.0 9.6 96.0 60.8 99.4 18.1 70.5 54.2 55.0 78.5 77.2 55.9 82.1 93.7 34.2 80.9 0.8 30.8 35.8 94.1 42.3 21.8 83.6 5.0 91.1 4.7 73.9 56.9 39.8 96.0 47.8 72.8 43.6 66.6 29.6 86.4 28.3 86.8 95.7 23.6 93.2 75.4 98.3 96.5 45.4 0.8 81.4 First 7 rows/columns of b: 41.3 48.7 70.7 28.6 69.1 24.6 1.8 62.0 93.5 55.7 75.7 44.0 40.2 57.6 92.8 74.3 33.6 93.0 61.4 80.8 25.3 15.1 11.9 83.2 36.7 71.8 93.8 15.4 19.8 5.5 54.3 16.1 11.8 82.3 38.1 92.6 15.9 4.5 75.6 66.7 16.7 74.9 79.1 1.7 52.5 52.2 22.8 20.0 52.3 First 7 rows/columns of copy of a: 72.6 85.5 81.0 9.6 96.0 60.8 99.4 18.1 70.5 54.2 55.0 78.5 77.2 55.9 82.1 93.7 34.2 80.9 0.8 30.8 35.8 94.1 42.3 21.8 83.6 5.0 91.1 4.7 73.9 56.9 39.8 96.0 47.8 72.8 43.6 66.6 29.6 86.4 28.3 86.8 95.7 23.6 93.2 75.4 98.3 96.5 45.4 0.8 81.4 First 7 rows/columns of copy of b: 41.3 48.7 70.7 28.6 69.1 24.6 1.8 62.0 93.5 55.7 75.7 44.0 40.2 57.6 92.8 74.3 33.6 93.0 61.4 80.8 25.3 15.1 11.9 83.2 36.7 71.8 93.8 15.4 19.8 5.5 54.3 16.1 11.8 82.3 38.1 92.6 15.9 4.5 75.6 66.7 16.7 74.9 79.1 1.7 52.5 52.2 22.8 20.0 52.3 First 7 rows/columns of sum (a + b): 113.9 134.3 151.7 38.2 165.1 85.4 101.2 80.0 164.0 109.8 130.6 122.6 117.4 113.4 174.9 167.9 67.8 174.0 62.2 111.6 61.0 109.2 54.1 105.0 120.3 76.8 184.9 20.1 93.7 62.4 94.1 112.1 59.6 155.1 81.7 159.2 45.5 90.9 104.0 153.5 112.5 98.6 172.3 77.0 150.9 148.7 68.3 20.9 133.8 First 7 rows/columns of difference (a - b): 31.2 36.8 10.3 -19.0 26.9 36.2 97.6 -43.9 -23.0 -1.5 -20.7 34.5 37.0 -1.7 -10.7 19.4 0.7 -12.1 -60.5 -49.9 10.5 79.0 30.4 -61.4 46.8 -66.9 -2.7 -10.8 54.0 51.4 -14.5 79.8 35.9 -9.5 5.5 -26.1 13.7 81.9 -47.3 20.2 79.0 -51.3 14.1 73.7 45.8 44.3 22.6 -19.2 29.1 a equals but not == aCopy ? true b equals but not == bCopy ? true After a.makeEmpty(3) and b.makeEmpty(5): First 8 rows/columns of a: 0.0 0.0 0.0 9.6 96.0 60.8 99.4 70.0 0.0 0.0 0.0 55.0 78.5 77.2 55.9 94.6 0.0 0.0 0.0 80.9 0.8 30.8 35.8 18.5 94.1 42.3 21.8 83.6 5.0 91.1 4.7 74.0 73.9 56.9 39.8 96.0 47.8 72.8 43.6 78.4 66.6 29.6 86.4 28.3 86.8 95.7 23.6 72.6 93.2 75.4 98.3 96.5 45.4 0.8 81.4 62.6 83.4 50.1 4.9 41.5 5.3 56.1 66.2 34.2 First 8 rows/columns of b: 0.0 0.0 0.0 0.0 0.0 24.6 1.8 32.7 0.0 0.0 0.0 0.0 0.0 40.2 57.6 90.5 0.0 0.0 0.0 0.0 0.0 80.8 25.3 35.0 0.0 0.0 0.0 0.0 0.0 93.8 15.4 20.3 0.0 0.0 0.0 0.0 0.0 82.3 38.1 37.0 92.6 15.9 4.5 75.6 66.7 16.7 74.9 94.9 79.1 1.7 52.5 52.2 22.8 20.0 52.3 4.7 28.5 75.5 67.3 72.7 26.0 13.8 5.9 96.9 a equals but not == aCopy ? false b equals but not == bCopy ? false