New in Mathematica 13.1 Mathematica Version 13.1 includes 90 completely new functions - plus 203 functions with substantial updates, new user interface features and enhanced compiler functionality. Stephen Wolframs Blog Entry announcing Version 13.1 Thread arrays at deep levels of other arrays with Threaded New language convenience functions for list manipulation: DeleteElements, DeleteAdjacentDuplicates, SymmetricDifference and UniqueElements Added functional programming convenience functions: ReplaceAt, MapApply, Until and SameAs Compute change of variables in integrals and differential equations with IntegrateChangeVariables and DSolveChangeVariables Support for fractional derivatives and fractional differential equations with FractionalD, CaputoD and an update to DSolve Compute derivatives of implicitly defined functions using ImplicitD Added several new types of structured arrays: PermutationMatrix, BlockDiagonalMatrix, LowerTriangularMatrix, UpperTriangularMatrix, BlockLowerTriangularMatrix and BlockUpperTriangularMatrix Interval evaluation via CenteredInterval or Interval added to multiple special mathematical functions Plot ratios of quantities with TernaryListPlot Enhanced support for the ScalingFunctions option in visualization functions, and added NominalScale and OrdinalScale VoronoiMesh now supports 3D Voronoi decompositions Reconstruct 1D, 2D and 3D meshes from point clouds using ReconstructionMesh EstimatedPointNormals can estimate normals to points in a point cloud Added functions for operations on graphs: GraphProduct, GraphJoin and GraphSum Emoji and more multilingual support Create 2D drop shadow effects with DropShadowing Several new shaders for graphics added: FlatShading, GouraudShading and PhongShading Interactive video recording from webcams and other devices with VideoCapture Interactive screen video recording with VideoScreenCapture New machine learning functions to plot impact of features on a model result: FeatureValueImpactPlot, FeatureImpactPlot, CumulativeFeatureImpactPlot and FeatureValueDependencyPlot New tree-related functions RootTree, UnlabeledTree, TreeLeafCount and numerous options to style and label trees Represent a family of chemical reactions symbolically with PatternReaction and apply such a reaction to a set of molecules with ApplyReaction Perform chemical conversions with ChemicalConvert ModelPredictiveController performs explicit constrained MPC controller design with 1-, 2- and ∞-norms DiscreteInputOutputModel implements a general nonlinear input output model New functions for type declaration and type specification syntax in compiled code and libraries: TypeDeclaration, CompiledExpressionDeclaration, LibraryFunctionDeclaration and TypeSpecifier Expanded support for type representation in compiled code with ForAllType, LiteralType, TypeEvaluate, CreateTypeInstance and TypeOf Call the evaluator from compiled code with InertEvaluate Create and dereference pointers for interacting with external libraries with ToRawPointer and FromRawPointer Added an "ExprStruct" data structure that represents an expression that can be modified without evaluation QuestionGenerator and QuestionSelector add further support for question & answer interfaces New default toolbar, annotation overlay and custom guide page creation See the complete list of what's new in the Wolfram Language with Mathematica 13.1 on the Wolfram Research website