To illustrate the use of tracers inside of an object, this page will follow adding a tracer to the clump object.

Inside of clumps.f90, ClumpDef, there is:

INTEGER :: iTracer=0

This integer indexes the position in q of the clump tracer. When it is set to 0, there is no slot in q that holds the tracer, hence no tracer is assigned to the clump object.

To add a tracer to the clump object, one must assign a slot in q to hold the tracer. This is done by adding the following to ProblemModuleInit in problem.f90:

CALL AddTracer(MyClump%iTracer, "ClumpTracer")