This cookbook provides an example of how to use the lazy-expression syntax
for if-else statements in Function expressions in the parameters files for 
aspect. In addition, the parameter file shows how to run aspect to just check
initial conditions are set correctly (by using and End time of zero and 
setting the solver tolerances to large values). It also uses a Function expression 
to refine the initial mesh at the top of the box.

The example includes these files:

mu_parser_temperature_example.prm       parameter file for aspect

muparser_if_temperature_example.py      python script that creates the same
                                        initial temperature as defined in the
                                        parameter file using lazy expression
temperature_muparser_if.pdf             figure output from python script

Figures showing the output of the cookbook are included in the cookbook section
of the manual /doc/manual/cookbooks/muparser-temperature-example.

- Magali Billen, UC Davis, mibillen@ucdavis.edu
- July, 2018.
