Include the contents of the given file into the FRED program.


include <filename>


This statement allows users to write modular FRED programs by using separate .fred files for each condition in a model. In addition, parameters and variables can be specified in their own .fred files. The include statement inserts the contents of the given file at the point where the include statement appears when the program is compiled.


Here we show include statements being used to include two .fred files called simpleflu.fred and params.fred into a FRED program. params.fred is assumed to be in the same directory as the file that contains the include statement. The full path to simpleflu.fred is given relative to the FRED_PROJECT directory that must be specified as an environment variable.

include $FRED_PROJECT/FRED-tutorials/simpleflu/simpleflu.fred
include params.fred


In addition to the FRED_PROJECT environment variable used in the above example, include statements can make use of the FRED_PATH environment variable. See the FRED Modeling Language Guide for details about how include statements interact with FRED_PATH.


If fred_compile cannot locate the file indicated by an include statement, it will raise an error. For example, if a FRED main.fred file included the line

include simpleflu.fred

but the file simpleflu.fred did not exist in the same directory as main.fred, the following error would be raised.

fred_compile -p main.fred
FRED Error (file ./main.fred):
Cannot open file simpleflu.fred


This statement was introduced in FRED 7. By convention, FRED files use the extension .fred, although this is not enforced by the FRED compiler.