Introduction

DIDASKO, the tutorial of Trilinos, offers a quick overview of Trilinos. The reader can find a variety of examples on several Trilinos packages. Each example is documented with comments and suggestions, some in the source file itself, and some others in the PDF document. The PDF version of the tutorial can be found in the Trilinos web page.

Usually, a Trilinos package interoperates with other Trilinos packages (and with external packages as well). To be used efficiently, the examples of DIDASKO would require the following compilation flags:

```--enable-epetra --enable-aztecoo --enable-amesos --enable-anasazi \
--enable-ifpack --enable-ml --enable-nox --enable-teuchos \
--enable-triutils
```

Most of the required packages are enabled by default. No example can effectively run without Epetra, and most require AztecOO and Triutils (this latter to generate the linear system matrix).

```#include "Didasko_ConfigDefs.h"
```

Then, the code checks for installed libraries, like for instance

```#if defined(HAVE_DIDASKO_EPETRA)
```

In the following, we report the source code of each of the examples. Packages are reported in alphabetical order.

Anasazi Examples

• Computation of the lowest eigenvalues and the corresponding eigenvectors of a symmetric matrix using a Block Krylov Schur solver: anasazi_ex1
• Computation of the lowest eigenvalues and the corresponding eigenvectors of a symmetric matrix using a Block Davidson solver: anasazi_ex2
• Computation of the lowest eigenvalues and the corresponding eigenvectors of a nonsymmetric matrix using a Block Krylov Schur solver: anasazi_ex3
• Computation of the lowest eigenvalues and the corresponding eigenvectors of a symmetric matrix using an LOBPCG solver: anasazi_ex4

EpetraExt Examples

• Generate a matrix using triutils and redistribute with Zoltan: epetraext_ex1
• Generate a linearproblem using triutils and redistribute with Zoltan: epetraext_ex2

ML Examples

• Two-level domain decomposition preconditioner with AztecOO and ML: ml_ex1
• Use of ML as a black-box smoothed aggregation preconditioner: ml_ex2

NOX Examples

• Simple nonlinear problem: nox_ex1
• Simple nonlinear PDE problem: nox_ex2