The Iterative Template Library (ITL) has two parts, iterative solvers and precondtioenrs. ITL provides a collection of sophisticated iterative solvers that use basic linear algebra packages such as the Matrix Template Library or Blitz++ for its basic linear algebra operations. The ITL has extended many of the ideas of the Iterative Methods Library (IML++), to make the library more flexible. On the other hand, ITL also provides a set of preconditioners which are designed for Matrix Template Library.

The ITL currently includes the following methods:

• Conjugate Gradient (cg)
• Conjugate Gradient Squared (cgs)
• BiConjugate Gradient (bicg)
• BiConjugate Gradient Stabilized (bicgstab)
• Chebyshev Iteration (cheby)
• Richardson Iteration (richardson)
• Generalized Conjugate Residual (gcr)
• Generalized Minimal Residual (gmres)
• Quasi-Minimal Residual Without Lookahead (qmr)
• Transpose Free Quasi-Minimal Residual Without Lookahead (tfqmr)

The ITL currently includes the following preconditioners:

• Incomplete Cholesky (cholesky)
• Incomplete LU without fill-in (ILU)
• Incomplete LU with n fill-in and with threshold (ILUT)
• SSOR

>