Introduction

This document details the thorns provided in the standard Cactus distribution for the output of grid variables, and describes how to set parameters for I/O and checkpointing/recovery using these thorns.

Input and output of data (I/O) in Cactus is provided by infrastructure thorns, which interact with the flesh via a fixed interface, which is described in the Users' Guide. The standard release of Cactus contains a number of thorns which provide so-called I/O methods implementing the actual I/O in a variety of data formats and styles. All these provided I/O methods use thorn IOUtil which provides general utilities for I/O (such as parsing parameter strings to decide which variables to output), and a general set of parameters which are inherited by the different I/O methods (such as the output directory). Thorn IOUtil by itself provides no I/O methods.

More information about I/O and visualisation of Cactus data can be found in the individual I/O thorns, and in the Visualization-HOWTO available on the Cactus web pages.