Parameters

All parameters defined in a thorn's param.ccl and all global parameters, appear as local variables of the corresponding CCTK data type in C source code, i.e. Integers and Booleans appear as CCTK_INT types (with nonzero/zero values for boolean yes/no), Reals as CCTK_REAL, and Keywords and String parameters as CCTK_STRING. These variables are read only, and changes should not be made to them. The effect of changing a parameter is undefined (at best).

Any routine using Cactus parameters should include at the top of the file the header

#include "cctk_Parameters.h"

The parameters should be declared as the last statement in the declaration part of the routine using them with the macro DECLARE_CCTK_PARAMETERS.