Each Trilinos package is a self-contained, independent piece of software with its own set of requirements, its own development team and group of users. Because of this, Trilinos itself is designed to respect the autonomy of packages. Trilinos offers a variety of ways for a particular package to interact with other Trilinos packages. It also offers a set of tools that can assist package developers with builds across multiple platforms, generating documentation and regression testing across a set of target platforms. At the same time, what a package must do to be called a Trilinos package is minimal, and varies with each package.
Basic Linear Algebra Libraries
- Epetra - Core linear algebra package. Facilitates
construction and manipulation of distributed and serial graphs, sparse and
dense matrices, vectors and multivectors.
- EpetraExt - Extensions to the core linear
algebra package, Epetra.
- Tpetra - Next-generation, templated version of
Petra, taking advantage of the newer advanced features of C++.
- Jpetra - Experimental Java version of the Petra
- Kokkos - Core kernel package.
- AztecOO - ILU-type preconditioner. See also
description under "Linear Solvers."
- IFPACK - Distributed algebraic preconditioner
package. Includes incomplete factorizations and relaxation-based
preconditioners in domain decomposition framework. Compatible with
- Ifpack2 - Contains preconditioners that operate on the templated
linear-algebra objects provided by the Tpetra package. Intended as a
templated replacement for Ifpack.
- ML - Multilevel, distributed memory
algebraic preconditioners. Provides multi-level, multigrid-like
preconditioners for distributed linear systems. Compatible with
- Teko - Blocked and segregated preconditioning package. Includes
a high level interface for manipulating block operators and creating
inverse operators using solver and preconditioning capabilities in
Trilinos. Utilities are provided that decompose large Epetra_CrsMatrix
objects into physically meaningful sub blocks.
- Epetra - Provides wrappers for select BLAS and
LAPACK routines. See also description under "Basic Linear Algebra
- Teuchos - Provides wrappers for select BLAS and
LAPACK routines. See also description under "Basic Linear Algebra
- Pliris - An object-oriented interface to a LU
solver for dense matrices on parallel platforms.
- AztecOO - Preconditioned Krylov solver package.
Supercedes Aztec 2.1. Solves linear systems of equations via preconditioned
Krylov methods. Uses Epetra objects, compatible with IFPACK, ML and
- Belos - Next-generation iterative solvers written
using a traits interface, meaning that it has no explicit dependence on any
concrete linear algebra library. Instead, it can be used with any concrete
linear algebra library that implements the Thyra abstract interfaces and even
- Komplex - Complex linear solver package. Solves
complex-valued linear systems via equivalent real
- Amesos - Direct solver classes.
Supports use of a growing list of third party direct solvers, including
DSCPACK, SuperLU, SuperLUDist and UMFPACK. Compatible with
- Amesos2 - Direct solver library/interface in Trilinos. Amesos2 provides
interfaces to third-party direct solvers for templated matrices and vectors
Nonlinear, Transient, and Optimization Solvers
- NOX - Nonlinear solver package.
Abstract and concrete classes for construction and solution of nonlinear
- LOCA - LOCA is a software library for
performing bifurcation analysis of large-scale applications. When implemented
with an application code, LOCA enables the tracking of solution branches as a
function of system parameters and the direct tracking of bifurcation points.
LOCA is designed to drive application codes that use Newton's method to
locate steady-state solutions to nonlinear problems.
- MOOCHO - MOOCHO (Multifunctional
Object-Oriented arCHitecture for Optimization) is designed to solve
large-scale, equality and inequality nonlinearly constrained, non-convex
optimization problems (i.e. nonlinear programs) using reduced-space
successive quadratic programming (SQP) methods.
- Piro - Piro is striving to be the single unifying
layer above all nonlinear solver, time integration, optimization, and UQ
- Rythmos - Rythmos is a transient integrator
for ordinary differential equations and differential-algebraic equations with
support for explicit, implicit, one-step and multi-step algorithms. The
fundamental design of Rythmos is aimed at supporting operator-split
algorithms, multi-physics applications, block linear algebra, and adjoint
- TriKota - TriKota is a convenience package that
builds the Dakota
framework underneath Trilinos as if it were a Trilinos package. Dakota
contains a wide array of algorithms for optimization and UQ.
- GlobiPack - The GlobiPack package contains a set
of interfaces and implementations for 1D globalization capabilities to be used
in nonlinear solvers, optimization solvers, and similar algorithms that require
globalization methods (e.g. line search and trust region methods).
- OptiPack - The OptiPack package contains
interfaces and concrete implementations of some basic optimization algorithms
based on Thyra. The globalization methods used are
implemented in GlobiPack.
- Anasazi - Anasazi is an extensible and
interoperable framework for large-scale eigenvalue algorithms. The motivation
for this framework is to provide a generic interface to a collection of
algorithms for solving large-scale eigenvalue problems. Anasazi is
interoperable because both the matrix and vectors (defining the eigenspace)
are considered to be opaque objects---only knowledge of the matrix and
vectors via elementary operations is necessary. An implementation of Anasazi
is accomplished via the use of interfaces. Current interfaces available
include Epetra and so any libraries that understand Epetra matrices and
vectors (such as AztecOO) may also be used in conjunction with
- Sacado - Sacado is a package for automatic
differentiation of C++ programs It provides simple yet fast and efficient
classes for forward, revers and Taylor polynomial mode automatic
differentiation using C++ template and operator overloading. The resulting
derivatives can be leverage in numerous ways including nonlinear solves with
NOX continuation and bifurcation analysis with LOCA optimization with MOOCHO, and time
integration wit Rythmos.
- Stokhos - Stokhos is a package for intrusive stochastic
Galerkin uncertainty quantification methods. It provides methods for computing
well-known intrusive stochastic Galerkin projections such as Polynomial Chaos and
Generalized Polynomial Chaos, interfaces for forming the resulting nonlinear systems,
and linear solver methods for solving block stochastic Galerkin linear systems.
- Claps - Claps is a collection of domain
decomposition preconditioners and solvers.
- Moertel - Mortar methods that can be used in a
large class of nonconforming situations such as the surface coupling of
different physical models, discretization schemes or non-matching
triangulations along interior interfaces of a domain.
Partitioning / Load Balancing
- Isorropia - Isorropia is a
partitioning and load balancing package, intended to assist with redistributing
objects such as matrices and matrix-graphs in a parallel execution setting,
to allow for more efficient computations. Isorropia is primarily an interface
to the Zoltan library.
- Zoltan - Zoltan is a toolkit of parallel services for dynamic,
unstructured, and/or adaptive simulations. Zoltan provides parallel dynamic load balancing and
related services for a wide variety of applications, including finite
element methods, matrix operations, particle methods, and crash simulations.
Zoltan also provides parallel graph coloring, matrix ordering, unstructured
communication tools, and distributed data directories.
Abstract Interfaces and Adapters
- Thyra - Abstract linear solver package. Replaces the
now-deprecated TSF family.
- PyTrilinos - Python interfaces to selected
- CTrilinos - C interfaces to selected Trilinos packages.
- ForTrilinos - ForTrilinos provides a set of
standards-conforming, potrable Fortran interfaces to Trilinos packages.
ForTrilinos is intended to minimal in its implementation, Relative to direct
interaction with Trilinos from C++, call Trilinos from Fortran via ForTrilinos
adds no overhead beyond that associated with a single additional function call.
The development of ForTrilinos is primarily user-driven, so new interfaces are
developed at the request of Trilinos users.
- WebTrilinos - Web interface to experiment with
Trilinos through a browser.
- Stratimikos - The package Stratimikos contains
a unified set of Thyra-based wrappers to linear solver and preconditioner
capabilities in Trilinos. The name Stratimikos was created from the Greek
words "stratigiki" and "grammikos" which which mean "strategy" and "linear in
English. The word "stratimikos" itself has not real meaning itself. The
Stratimikos package is also a place where unified testing of linear solvers
and preconditioners can be performed.
- FEI - A general interface for assembling finite-element data
into a system of linear equations.
- TrilinosCouplings - A collection of interfaces between packages.
Mesh Generation, Improvement, and Adaptivity
- Mesquite - Applies a variety of node-movement
algorithms to improve the quality and/or adapt a given mesh.
- PAMGEN - PAMGEN creates hexahedral or quadrilateral
(in 2D) finite element meshes of simple shapes (cubes and cylinders) in parallel.
When linked to an application as a library, it allows each process of a parallel
simulation to generate its finite element domain representation at execution time.
- Intrepid - Intrepid is a library of interoperable
tools for compatible discretizations of Partial Differential Equations
(PDEs). Included with the Trilinos 10.0 release is the "expert version" of Intrepid.
This version is intended primarily for application developers
who want to reuse large parts of their existing code frameworks such as I/O,
data structures, assembly routines, etc. while gaining access to advanced discretization
capabilities provided by Intrepid.
- phdMesh - The Parallel Heterogeneous Dynamic unstructured Mesh
(phdMesh) data structure library is intended to be component used within a finite element
or finite volume library or code. The phdMesh data structure supports arbitrary unstructured
mesh connectivity, application-defined groupings of mesh entities, and application-defined
computational field data. The included parallel-performance test application performs dynamic
load balancing and parallel geometric proximity searching on the contrived "gears" test
- STK - Contains capabilities intended to
support massively parallel multi-physics computations on dynamically
changing unstructured meshes. The primary capability in the STK package
is the mesh database which supports creation and manipulation of mesh
entities (nodes, elements etc) and computational field data defined
on the mesh. STK also contains sub-libraries that support geometric
proximity searches, assembly into linear-systems, etc.
- Teuchos - Common tools package.
- TriUtils - TriUtils is a package of utilites used
by many of the Trilinos packages.
- EpetraExt - Matrix/Vector read/write utilities.
See also description under "Basic Linear Algebra Libraries."
- RTOp - RTOp (reduction/transformation operators)
provides the basic mechanism for implementing vector operations in a flexible
and efficient manner.
- Galeri - Galeri is a package for generating linear
systems used by many of the Trilinos packages for examples and
- ThreadPool - A minimalistic interface for orchestrating the thread-parallel
execution of functions within a pool of threads.
- Optika - The Optika package provides trilinos
developers with easy access to GUI input methods for their programs.
- SEACAS - The Sandia Engineering Analysis Code Access System (SEACAS) is
a collection of applications for manipulating Exodus databases. The Exodus
database is a model developed to facilitate pre- and post-processing and
code-to-code exchange of finite element analysis data. The Exodus database
is a random access, machine independent binary format that is accessed via
a C, C++, or Fortran API. SEACAS applications include Exodus database
manipulation, query, translation, parallel decomposition and composition,
comparison, parameterization, and mapping utilities.
PDE discretization tools
- Phalanx - Phalanx is a local field evaluation kernel specifically designed for general partial differential equation solvers.
- Intrepid - Intrepid is a library of interoperable tools for compatible discretizations of Partial Differential Equations (PDEs). The current version is intended primarily for application developers who want to reuse large parts of their existing code frameworks such as I/O, data structures, assembly routines, etc. while gaining access to advanced discretization capabilities provided by Intrepid.
- Shards - Shards is a suite of common tools for numerical and topological data that facilitate interoperability between typical software modules used to solve Partial Differential Equations (PDEs) by finite element, finite volume and finite difference methods. Shards provides two categories of tools: templated multi-dimensional array implementation and templated cell topologies.
- Didasko - Didasko is the Trilinos tutorial, and
contains several examples, detailed descriptions, tips, and suggestions for
most Trilinos packages.
- New_Package - A sample Trilinos package
containing all of the infrastructure to install a new package into the
Trilinos framework. Contains the basic directory structure, a collection of
sample configuration and build files and a sample "Hello World"
- Sundance - Sundance is a system for rapid development of high-performance
finite-element solutions of partial differential equations.