C# MatrixD类代码示例

 public void ConstructorException2()
 {
     MatrixD m = new MatrixD(new double[,] {{ 1, 2 },
                                      { 3, 4 },
                                      { 5, 6 }});
       new EigenvalueDecompositionD(m);
 }

        public void Test1()
        {
            MatrixD a = new MatrixD(new double[,] { { 2, -1, 0},
                                             { -1, 2, -1},
                                             { 0, -1, 2} });

              CholeskyDecompositionD d = new CholeskyDecompositionD(a);

              Assert.AreEqual(true, d.IsSymmetricPositiveDefinite);

              MatrixD l = d.L;

              Assert.AreEqual(0, l[0, 1]);
              Assert.AreEqual(0, l[0, 2]);
              Assert.AreEqual(0, l[1, 2]);

              Assert.IsTrue(MatrixD.AreNumericallyEqual(a, l * l.Transposed));

              Assert.IsTrue(MatrixD.AreNumericallyEqual(a, l * l.Transposed));

              // Check solving of linear equations.
              MatrixD x = new MatrixD(new double[,] { { 1, 2},
                                             { 3, 4},
                                             { 5, 6} });
              MatrixD b = a * x;

              Assert.IsTrue(MatrixD.AreNumericallyEqual(x, d.SolveLinearEquations(b)));
        }

        public void TestRandomA()
        {
            RandomHelper.Random = new Random(1);

              for (int i = 0; i < 100; i++)
              {
            // Create A.
            MatrixD a = new MatrixD(3, 3);
            RandomHelper.Random.NextMatrixD(a, 0, 1);

            LUDecompositionD d = new LUDecompositionD(a);

            if (d.IsNumericallySingular == false)
            {
              // Check solving of linear equations.
              MatrixD b = new MatrixD(3, 2);
              RandomHelper.Random.NextMatrixD(b, 0, 1);

              MatrixD x = d.SolveLinearEquations(b);
              MatrixD b2 = a * x;
              Assert.IsTrue(MatrixD.AreNumericallyEqual(b, b2, 0.01));

              MatrixD aPermuted = d.L * d.U;
              Assert.IsTrue(MatrixD.AreNumericallyEqual(aPermuted, a.GetSubmatrix(d.PivotPermutationVector, 0, 2)));
            }
              }
        }

        public void TestMatricesWithoutFullRank()
        {
            MatrixD a = new MatrixD(3, 3);
              SingularValueDecompositionD svd = new SingularValueDecompositionD(a);
              Assert.AreEqual(0, svd.NumericalRank);
              Assert.AreEqual(svd.SingularValues[0], svd.Norm2);
              double condNumber = svd.ConditionNumber;

              a = new MatrixD(new double[,] { { 1, 2, 3 }, { 4, 5, 6 }, { 4, 5, 6 } });
              svd = new SingularValueDecompositionD(a);
              Assert.AreEqual(2, svd.NumericalRank);
              Assert.AreEqual(svd.SingularValues[0], svd.Norm2);
              Assert.IsTrue(MatrixD.AreNumericallyEqual(a, svd.U * svd.S * svd.V.Transposed));
              svd = new SingularValueDecompositionD(a.Transposed);
              Assert.AreEqual(2, svd.NumericalRank);
              Assert.IsTrue(MatrixD.AreNumericallyEqual(a.Transposed, svd.U * svd.S * svd.V.Transposed));
              Assert.IsTrue(MatrixD.AreNumericallyEqual(a.Transposed, svd.U * svd.S * svd.V.Transposed)); // Repeat to test with cached values.
              Assert.AreEqual(svd.SingularValues[0], svd.Norm2);
              condNumber = svd.ConditionNumber;

              a = new MatrixD(new double[,] { { 1, 2 }, { 1, 2 }, { 1, 2 } });
              svd = new SingularValueDecompositionD(a);
              Assert.AreEqual(1, svd.NumericalRank);
              Assert.IsTrue(MatrixD.AreNumericallyEqual(a, svd.U * svd.S * svd.V.Transposed));
              Assert.AreEqual(svd.SingularValues[0], svd.Norm2);
              condNumber = svd.ConditionNumber;
        }

        internal MyClipmapHandler(uint id, MyClipmapScaleEnum scaleGroup, MatrixD worldMatrix, Vector3I sizeLod0, RenderFlags additionalFlags)
        {
            m_clipmapBase = new MyClipmap(id, scaleGroup, worldMatrix, sizeLod0, this);
            m_renderFlags = additionalFlags;

            MyClipmap.AddToUpdate(MyEnvironment.CameraPosition, m_clipmapBase);
        }

 public override void OnWorldPositionChanged(ref MatrixD worldMatrix)
 {
     var forward = worldMatrix.Forward;
     m_origin = worldMatrix.Translation + forward * m_originOffset;
     FrontPoint = m_origin + m_rayLength * forward;
     Center = (m_origin + FrontPoint) * 0.5f;
 }

 public MyRenderAtmosphere(uint id, string debugName, string model, MatrixD worldMatrix, MyMeshDrawTechnique drawTechnique, RenderFlags renderFlags, float atmosphereRadius, float planetRadius, Vector3 atmosphereWavelengths)
     : base(id, debugName,model, worldMatrix,drawTechnique, renderFlags)
 {
     m_atmosphereWavelengths = atmosphereWavelengths;
     m_atmosphereRadius = atmosphereRadius;
     m_planetRadius = planetRadius;
 }

 public IMyClipmapCell CreateCell(MyClipmapScaleEnum scaleGroup, MyCellCoord cellCoord, ref MatrixD worldMatrix)
 {
     var cell = new MyClipmapCellProxy(cellCoord, ref worldMatrix, m_massiveCenter, m_massiveRadius, m_renderFlags);
     cell.SetVisibility(false);
     cell.ScaleGroup = scaleGroup;
     return cell;
 }

		public void TestToVector()
		{
			var m1 = new MatrixD(new double[] { 1, 2, 3, 4 }, 2, 2);
			var v1 = m1.ToVector();

			Assert.AreEqual<VectorD>(new VectorD(1, 2, 3, 4), v1);
		}

            internal MyLodMeshMerge(MyClipmap parentClipmap, int lod, int lodDivisions, ref MatrixD worldMatrix, ref Vector3D massiveCenter, float massiveRadius, RenderFlags renderFlags)
            {
                Debug.Assert(parentClipmap != null, "Parent clipmap cannot be null");
                Debug.Assert(lod >= 0, "Lod level must be non-negative");
                Debug.Assert(lodDivisions >= 0, "Invalid number of lod divisions");
                m_parentClipmap = parentClipmap;
                m_lod = lod;
                m_lodDivisions = lodDivisions;

                if (m_lodDivisions <= 0)
                    return;

                m_dirtyProxyIndices = new HashSet<int>();
                m_cellProxyToAabbProxy = new Dictionary<MyClipmapCellProxy, int>();
                m_boundingBoxes = new MyDynamicAABBTreeD(Vector3D.Zero);

                int cellCount = lodDivisions*lodDivisions*lodDivisions;
                m_mergeJobs = new MergeJobInfo[cellCount];
                m_mergedLodMeshProxies = new MyClipmapCellProxy[cellCount];
                m_trackedActors = new HashSet<MyActor>[cellCount];

                for (int divideIndex = 0; divideIndex < cellCount; ++divideIndex)
                {
                    m_mergedLodMeshProxies[divideIndex] = new MyClipmapCellProxy(new MyCellCoord(Lod, GetCellFromDivideIndex(divideIndex)), ref worldMatrix, massiveCenter, massiveRadius, renderFlags, true);
                    m_mergeJobs[divideIndex] = new MergeJobInfo { CurrentWorkId = 0, LodMeshesBeingMerged = new List<LodMeshId>(), NextPossibleMergeStartTime = MyCommon.FrameCounter };
                    m_trackedActors[divideIndex] = new HashSet<MyActor>();
                    m_dirtyProxyIndices.Add(divideIndex);
                }
            }

 public MyRenderBatch(uint id, string debugName, MatrixD worldMatrix, RenderFlags renderFlags, List<MyRenderBatchPart> batchParts)
     : base(id, debugName, worldMatrix, renderFlags)
 {
     m_localAABB = BoundingBoxD.CreateInvalid();
     m_batchParts.Clear();
     m_batchParts.AddList(batchParts);
 }

        //--------------------------------------------------------------
        /// <summary>
        /// Creates the principal component analysis for the given list of points.
        /// </summary>
        /// <param name="points">
        /// The list of data points. All points must have the same 
        /// <see cref="VectorD.NumberOfElements"/>.
        /// </param>
        /// <exception cref="ArgumentNullException">
        /// <paramref name="points"/> is <see langword="null"/>.
        /// </exception>
        /// <exception cref="ArgumentException">
        /// <paramref name="points"/> is empty.
        /// </exception>
        public PrincipalComponentAnalysisD(IList<VectorD> points)
        {
            if (points == null)
            throw new ArgumentNullException("points");
              if (points.Count == 0)
            throw new ArgumentException("The list of points is empty.");

              // Compute covariance matrix.
              MatrixD covarianceMatrix = StatisticsHelper.ComputeCovarianceMatrix(points);

              // Perform Eigenvalue decomposition.
              EigenvalueDecompositionD evd = new EigenvalueDecompositionD(covarianceMatrix);

              int numberOfElements = evd.RealEigenvalues.NumberOfElements;
              Variances = new VectorD(numberOfElements);
              V = new MatrixD(numberOfElements, numberOfElements);

              // Sort eigenvalues by decreasing value.
              // Since covarianceMatrix is symmetric, we have no imaginary eigenvalues.
              for (int i = 0; i < Variances.NumberOfElements; i++)
              {
            int index = evd.RealEigenvalues.IndexOfLargestElement;

            Variances[i] = evd.RealEigenvalues[index];
            V.SetColumn(i, evd.V.GetColumn(index));

            evd.RealEigenvalues[index] = double.NegativeInfinity;
              }
        }

        public MyEntity Spawn(MyFixedPoint amount, MatrixD worldMatrix, MyEntity owner = null)
        {
            if (Content is MyObjectBuilder_BlockItem)
            {
                Debug.Assert(MyFixedPoint.IsIntegral(amount), "Spawning fractional number of grids!");

                var blockItem = Content as MyObjectBuilder_BlockItem;
                var builder = MyObjectBuilderSerializer.CreateNewObject(typeof(MyObjectBuilder_CubeGrid)) as MyObjectBuilder_CubeGrid;
                builder.GridSizeEnum = MyCubeSize.Small;
                builder.IsStatic = false;
                builder.PersistentFlags |= MyPersistentEntityFlags2.InScene | MyPersistentEntityFlags2.Enabled;
                builder.PositionAndOrientation = new MyPositionAndOrientation(worldMatrix);

                var block = MyObjectBuilderSerializer.CreateNewObject(blockItem.BlockDefId) as MyObjectBuilder_CubeBlock;
                builder.CubeBlocks.Add(block);

                MyCubeGrid firstGrid = null;
                for (int i = 0; i < amount; ++i)
                {
                    builder.EntityId = MyEntityIdentifier.AllocateId();
                    block.EntityId = MyEntityIdentifier.AllocateId();
                    MyCubeGrid newGrid = MyEntities.CreateFromObjectBuilder(builder) as MyCubeGrid;
                    firstGrid = firstGrid ?? newGrid;
                    MyEntities.Add(newGrid);
                    Sandbox.Game.Multiplayer.MySyncCreate.SendEntityCreated(builder);
                }
                return firstGrid;
            }
            else
                return MyFloatingObjects.Spawn(new MyPhysicalInventoryItem(amount, Content),worldMatrix, owner != null ? owner.Physics : null);
        }

        void IMyClipmapCell.UpdateWorldMatrix(ref VRageMath.MatrixD worldMatrix, bool sortIntoCullObjects)
        {
            m_worldMatrix = worldMatrix;

            Matrix m = m_worldMatrix * Matrix.CreateScale(m_scale) * Matrix.CreateTranslation(m_translation);
            m_actor.SetMatrix(ref m);
        }

        public void DeterminantException()
        {
            MatrixD a = new MatrixD(new double[,] { { 1, 2 }, { 5, 6 }, { 0, 1 } });

              LUDecompositionD d = new LUDecompositionD(a);
              double det = d.Determinant;
        }