The Template Numerical Toolkit (or TNT) is a software library for manipulating vectors and matrices in C++

C++

C++ is a statically typed, free-form, multi-paradigm, compiled, general-purpose programming language. It is regarded as an intermediate-level language, as it comprises a combination of both high-level and low-level language features. It was developed by Bjarne Stroustrup starting in 1979 at Bell...

 created by the U.S. National Institute of Standards and Technology

National Institute of Standards and Technology

The National Institute of Standards and Technology , known between 1901 and 1988 as the National Bureau of Standards , is a measurement standards laboratory, otherwise known as a National Metrological Institute , which is a non-regulatory agency of the United States Department of Commerce...

.
TNT provides the fundamental linear algebra operations (for example, matrix multiplication

Matrix multiplication

In mathematics, matrix multiplication is a binary operation that takes a pair of matrices, and produces another matrix. If A is an n-by-m matrix and B is an m-by-p matrix, the result AB of their multiplication is an n-by-p matrix defined only if the number of columns m of the left matrix A is the...

). TNT is analogous to the BLAS

Blas

Blas is mainly a Spanish given name and surname, related to Blaise. It may refer to-Places:*Piz Blas, mountain in Switzerland*San Blas , many places - see separate article, also**Cape San Blas Light, lighthouse...

 library used by LAPACK

LAPACK

-External links:* : a modern replacement for PLAPACK and ScaLAPACK* on Netlib.org* * * : a modern replacement for LAPACK that is MultiGPU ready* on Sourceforge.net* * optimized LAPACK for Solaris OS on SPARC/x86/x64 and Linux* * *...

. Higher level algorithms, such as LU decomposition

LU decomposition

In linear algebra, LU decomposition is a matrix decomposition which writes a matrix as the product of a lower triangular matrix and an upper triangular matrix. The product sometimes includes a permutation matrix as well. This decomposition is used in numerical analysis to solve systems of linear...

 and singular value decomposition

Singular value decomposition

In linear algebra, the singular value decomposition is a factorization of a real or complex matrix, with many useful applications in signal processing and statistics....

, are provided by JAMA

JAMA (numerical linear algebra library)

JAMA is a software library for performing numerical linear algebra tasks created at NIST similar in functionality to LAPACK. Versions exist for both C++ and the Java programming language. The C++ version uses the Template Numerical Toolkit for lower-level operations. The Java version provides...

, also developed at NIST, which uses TNT.

The major features of TNT are:

• All classes are template classes, and, therefore, work with float, double, or other user-defined number types.
• Matrices can be stored in row-major order
  Row-major order
  In computing, row-major order and column-major order describe methods for storing multidimensional arrays in linear memory. Following standard matrix notation, rows are numbered by the first index of a two-dimensional array and columns by the second index. Array layout is critical for correctly...
  
   or column-major order for Fortran
  Fortran
  Fortran is a general-purpose, procedural, imperative programming language that is especially suited to numeric computation and scientific computing...
  
   compatibility.
• The library is simply a collection of header files, and so, does not need to be independently compiled.
• Some support for sparse matrix storage is provided.
• The source code is in the public domain
  Public domain
  Works are in the public domain if the intellectual property rights have expired, if the intellectual property rights are forfeited, or if they are not covered by intellectual property rights at all...
  
  .

TNT is mature and NIST classifies its development status as active maintenance.

The principal designer of TNT is Roldan Pozo.