GfsDefine

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Revision as of 17:22, 7 August 2012
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(corrected relation to GfsInclude)
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GeordieMcBain (Talk | contribs)
(noted that m4 builtins are accessible if prefixed with m4_)
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Macros may be used but not defined in external files included via [[GfsInclude]]. Macros may be used but not defined in external files included via [[GfsInclude]].
 +
 +Macro definitions can use builtins from [http://www.gnu.org/savannah-checkouts/gnu/m4/manual/m4-1.4.16/html_node m4], prefixing them with ''m4_''.
<examples/> <examples/>

Revision as of 16:28, 9 August 2012

Define is used to define text macros in parameter files, similar to the macros of the C preprocessor (and still more similar to those of m4).

Examples of valid macros are:

Define PI 3.14159265359
Define SQUARE(x) (x*x)
Define REYNOLDS(U,L,nu) (U*L/nu)

Note that Define macros are more general than the C macros which can be defined using GfsGlobal. They apply to the parameter file as a whole rather than just to the GfsFunctions. For example, this parameter file:

...
Define LEVEL 7
...
Refine LEVEL
...
OutputSimulation { start = end } sim-LEVEL.gfs
...

will result in Gerris generating a simulation file called sim-7.gfs.

Note that macro support needs to be turned on explicitly (using the -m or -D options when starting gerris). Note also that the -m or -D options should not be used when restarting a simulation from a (binary) simulation file (e.g. created using GfsOutputSimulation).

Macros may be used but not defined in external files included via GfsInclude.

Macro definitions can use builtins from m4, prefixing them with m4_.

Examples

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