                               IDA
                    Release 2.9.0, September 2016
                 Alan C. Hindmarsh and Radu Serban 
            Center for Applied Scientific Computing, LLNL


IDA is a package for the solution of differential-algebraic equation
(DAE) systems.  It is written in C, but derived from the package DASPK
[4,5], which is written in FORTRAN. 

IDA can be used both on serial and parallel computers.  The main
difference is in the NVECTOR module of vector kernels.  The desired
version is obtained when compiling the example files by linking the
appropriate library of NVECTOR kernels.  In the parallel versions,
communication between processors is done with MPI, with OpenMP, 
or with Pthreads.

When used with the serial NVECTOR module, IDA provides both direct 
(dense and band) linear solvers and preconditioned Krylov (iterative) 
linear solvers. Three different iterative solvers are available: scaled 
preconditioned GMRES (SPGMR), scaled preconditioned BiCGStab (SPBCG), and 
scaled preconditioned TFQMR (SPTFQMR). When IDA is used with the parallel 
NVECTOR module, only the Krylov linear solvers are available.  For the 
latter case, in addition to the basic solver, the IDA package also contains 
a preconditioner module called IDABBDPRE, which provides a band-block-diagonal 
preconditioner.

IDA is part of a software family called SUNDIALS: SUite of Nonlinear and 
DIfferential/ALgebraic equation Solvers [3].  This suite consists of CVODE, 
CVODES, ARKode, IDA, IDAS, and KINSOL.  The directory structure of the 
package supplied reflects this family relationship.

For use with Fortran applications, a set of Fortran/C interface routines,
called FIDA, is also supplied.  These are written in C, but assume that
the user calling program and all user-supplied routines are in Fortran.

Several examples problem programs are included, covering both serial
and parallel cases, both small and large problem sizes, and both
linear and nonlinear problems.

The notes below provide the location of documentation, directions for the 
installation of the IDA package, and relevant references. Following that 
is a brief history of revisions to the package.


A. Documentation
----------------

/sundials/doc/ida/ contains PDF files for the IDA User Guide [1] (ida_guide.pdf)
and the IDA Examples [2] (ida_examples.pdf) documents.


B. Installation
---------------

For basic installation instructions see the file /sundials/INSTALL_GUIDE.pdf. 
For complete installation instructions see the "Installation Procedure"
chapter in the IDA User Guide.


C. References
-------------

[1] A. C. Hindmarsh, R. Serban, and A. Collier, "User Documentation for IDA v2.9.0," 
    LLNL technical report UCRL-SM-208112, March 2016.

[2] A. C. Hindmarsh, R. Serban, and A. Collier, "Example Programs for IDA v2.9.0," 
    LLNL technical report UCRL-SM-208113, March 2016.

[3] A. C. Hindmarsh, P. N. Brown, K. E. Grant, S. L. Lee, R. Serban, 
    D. E. Shumaker, and C. S. Woodward, "SUNDIALS, Suite of Nonlinear and 
    Differential/Algebraic Equation Solvers," ACM Trans. Math. Softw., 
    31(3), pp. 363-396, 2005.

[4] P. N. Brown, A. C. Hindmarsh, and L. R. Petzold, Using Krylov Methods 
    in the Solution of Large-Scale Differential-Algebraic Systems, 
    SIAM J. Sci. Comp., 15 (1994), pp. 1467-1488.

[5] P. N. Brown, A. C. Hindmarsh, and L. R. Petzold, Consistent Initial 
    Condition Calculation for Differential-Algebraic Systems, 
    SIAM J. Sci. Comp., 19 (1998), pp. 1495-1512.


D. Releases
-----------

v. 2.9.0   - Sep. 2016
v. 2.8.2   - Aug. 2015
v. 2.8.1   - Mar. 2015
v. 2.8.0   - Mar. 2015
v. 2.7.0   - Mar. 2012
v. 2.6.0   - May  2009
v. 2.5.0   - Nov. 2006
v. 2.4.0   - Mar. 2006
v. 2.3.0   - Apr. 2005
v. 2.2.2   - Mar. 2005
v. 2.2.1   - Jan. 2005
v. 2.2.0   - Dec. 2004
v. 2.0     - Jul. 2002 (first SUNDIALS release)
v. 1.0     - Feb. 1999 (date written)
