Log value distribution for consistent mappings

[uekerman]

Please describe the problem you are trying to solve.

It is sometimes difficult to quickly see whether a mapping does a good job or not. For a consistent mapping, one wants that the distribution of values (e.g. the average) stays the same (is this actually true?).

Describe the solution you propose.

We already give statistics on the computeMapping of NN and NP:

Mapping distance min:0 max:0.08 avg: 0.048 var: 0.000896 cnt: 25

We could log similar information for the actual values in each map call.

Pressure values before mapping (Fluid_Mesh) min:-10234 max:12365 avg: 10.23 var: ... cnt: 345
Pressure values after mapping (Solid_Mesh) min:-10000 max:12400 avg: 10.30 var: ... cnt: 112

I did not yet think much about details and wording.

For parallel participants, this would, of course, require global communication. So, there should be a way to switch this off, e.g. only have this for Debug builds.

What could be the equivalent for conservative mappings?

[mtree22]

The equivalent for conservative mappings would be that the sum of the values on each mesh are equivalent:

Force values before mapping (Fluid_Mesh) min:-10234 max:12365 sum: 10.23 var: ... cnt: 345
Force values after mapping (Solid_Mesh) min:-10000 max:12400 sum: 10.30 var: ... cnt: 112

I would very much appreciate this, by the way