> java MatrixTester First 7 rows/columns of a: 57.7 21.6 86.1 93.1 46.1 78.0 26.0 31.4 54.8 55.6 2.6 33.1 16.6 55.3 23.2 60.1 79.5 66.1 66.1 16.9 36.6 85.8 87.5 1.7 48.8 26.7 62.2 51.9 78.8 12.4 78.0 89.1 86.3 20.5 94.5 39.6 83.7 33.5 59.0 51.0 17.6 61.1 45.2 16.6 92.0 33.4 3.8 1.3 89.9 First 7 rows/columns of b: 50.1 6.3 29.3 26.1 86.1 79.0 1.8 76.1 73.8 92.6 68.5 74.7 84.1 60.9 60.3 95.9 93.8 70.0 26.6 9.3 19.7 55.7 6.2 55.3 3.2 77.8 22.7 26.2 62.0 26.2 3.8 89.6 29.8 31.1 63.2 42.6 35.1 43.7 80.6 39.0 99.4 89.8 52.9 56.7 27.2 64.0 44.0 94.8 19.7 First 7 rows/columns of copy of a: 57.7 21.6 86.1 93.1 46.1 78.0 26.0 31.4 54.8 55.6 2.6 33.1 16.6 55.3 23.2 60.1 79.5 66.1 66.1 16.9 36.6 85.8 87.5 1.7 48.8 26.7 62.2 51.9 78.8 12.4 78.0 89.1 86.3 20.5 94.5 39.6 83.7 33.5 59.0 51.0 17.6 61.1 45.2 16.6 92.0 33.4 3.8 1.3 89.9 First 7 rows/columns of copy of b: 50.1 6.3 29.3 26.1 86.1 79.0 1.8 76.1 73.8 92.6 68.5 74.7 84.1 60.9 60.3 95.9 93.8 70.0 26.6 9.3 19.7 55.7 6.2 55.3 3.2 77.8 22.7 26.2 62.0 26.2 3.8 89.6 29.8 31.1 63.2 42.6 35.1 43.7 80.6 39.0 99.4 89.8 52.9 56.7 27.2 64.0 44.0 94.8 19.7 First 7 rows/columns of sum (a + b): 107.8 27.9 115.4 119.2 132.2 156.9 27.8 107.5 128.6 148.2 71.2 107.8 100.6 116.2 83.5 156.0 173.3 136.1 92.8 26.2 56.3 141.5 93.6 57.0 52.0 104.5 84.8 78.1 140.8 38.7 81.8 178.7 116.1 51.6 157.6 82.2 118.7 77.1 139.6 90.0 117.0 150.8 98.1 73.4 119.2 97.4 47.8 96.1 109.6 First 7 rows/columns of difference (a - b): 7.6 15.3 56.8 67.0 -40.0 -1.0 24.1 -44.7 -19.0 -37.1 -65.9 -41.6 -67.5 -5.5 -37.1 -35.9 -14.4 -3.9 39.5 7.6 16.9 30.2 81.3 -53.6 45.6 -51.1 39.5 25.7 16.8 -13.8 74.2 -0.5 56.5 -10.5 31.3 -3.0 48.6 -10.2 -21.6 12.0 -81.7 -28.7 -7.7 -40.1 64.8 -30.6 -40.2 -93.5 70.2 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 93.1 46.1 78.0 26.0 35.5 0.0 0.0 0.0 2.6 33.1 16.6 55.3 3.8 0.0 0.0 0.0 66.1 66.1 16.9 36.6 87.3 85.8 87.5 1.7 48.8 26.7 62.2 51.9 40.5 78.8 12.4 78.0 89.1 86.3 20.5 94.5 17.2 39.6 83.7 33.5 59.0 51.0 17.6 61.1 54.4 45.2 16.6 92.0 33.4 3.8 1.3 89.9 79.1 56.7 17.2 5.3 0.4 58.8 81.3 99.0 76.4 First 8 rows/columns of b: 0.0 0.0 0.0 0.0 0.0 79.0 1.8 4.1 0.0 0.0 0.0 0.0 0.0 84.1 60.9 23.5 0.0 0.0 0.0 0.0 0.0 9.3 19.7 41.4 0.0 0.0 0.0 0.0 0.0 22.7 26.2 90.9 0.0 0.0 0.0 0.0 0.0 31.1 63.2 57.5 42.6 35.1 43.7 80.6 39.0 99.4 89.8 40.6 52.9 56.7 27.2 64.0 44.0 94.8 19.7 85.9 31.0 46.2 62.3 39.3 35.3 92.3 82.6 45.9 a equals but not == aCopy ? false b equals but not == bCopy ? false