Annette Osprey
Bit-comparsion Testing
Standard robustness tests involve varying the following:
- restart frequency
- number of processors
Restart Test
Set the restart frequency to 1 day and the run length to 3 days. Then run two tests:
- A continuous 3 day run
- A run in 1 day chunks
Compare dumps using cumf.
Processor Test
Set up a 1 day run with a 1 day restart dump. Then run the job on several arrangements of processors. It's best to vary the EW number, NS number and overall number of processors, eg:
- 1x8
- 2x2
- 4x4
- 2x4
Compare dumps using cumf.
Debugging
If fields don't compare, set the model to write extra dumps at various points in the code to narrow down where the output first diverges. Then work out array points which differ and step through the code, writing out values.
Further testing
Some calculations are not done every timestep and so it can sometimes be useful to repeat these tests over longer periodds of time.