public void GetLowerTriangleWide()
 {
   DoubleMatrix a = new DoubleMatrix(2,3);
   a[0,0] = 1;
   a[0,1] = 2;
   a[0,2] = 3;
   a[1,0] = 4;
   a[1,1] = 5;
   a[1,2] = 6;
   DoubleMatrix b = a.GetLowerTriangle();
   
   Assert.AreEqual(b.RowLength, a.RowLength);
   Assert.AreEqual(b.ColumnLength, a.ColumnLength);
   Assert.AreEqual(b[0,0], a[0,0]);
   Assert.AreEqual(b[0,1], 0);
   Assert.AreEqual(b[0,2], 0);
   Assert.AreEqual(b[1,0], a[1,0]);
   Assert.AreEqual(b[1,1], a[1,1]);
   Assert.AreEqual(b[1,2], 0);
 }
 public void GetLowerTriangleLong()
 {
   DoubleMatrix a = new DoubleMatrix(3,2);
   a[0,0] = 1;
   a[0,1] = 2;
   a[1,0] = 4;
   a[1,1] = 5;
   a[2,0] = 7;
   a[2,1] = 8;
   DoubleMatrix b = a.GetLowerTriangle();
   
   Assert.AreEqual(b.RowLength, a.RowLength);
   Assert.AreEqual(b.ColumnLength, a.ColumnLength);
   Assert.AreEqual(b[0,0], a[0,0]);
   Assert.AreEqual(b[0,1], 0);
   Assert.AreEqual(b[1,0], b[1,0]);
   Assert.AreEqual(b[1,1], a[1,1]);
   Assert.AreEqual(b[2,0], b[2,0]);
   Assert.AreEqual(b[2,1], b[2,1]);    
 }