Current In  == 0.7658220366
Current Out == 0.7658343481
Current In - Out == -1.231e-05

I.S. quadtree 13 levels, abs_tau_flux == 1.000e-04    size == 76376805

(apprx) Current In  == 0.7657741516
(apprx) Current Out == 0.7657625209
(apprx) Current In - Out == 1.163e-05

…1e-10.

(store_samples needs to be fixed still)

Set use_eggs=false to try uniform absorption and see that it is preserved to machine precision on all domains.

While per-domain discrepancies are <1e-6, the total metric gives 1e-2.
This could indicate a problem with synchronizing shared boundary faces,
or it could be that my test is wrong.

Domain[59] excess== 0.00000000068
Domain[60] excess== 0.00000000306
Domain[61] excess==-0.00000000186
Domain[62] excess==-0.00000000186
Domain[63] excess== 0.00000000071
Entire     excess== 0.02622323856
  leak:1.68e+01  src:1.00e+00  rem:-1.58e+01
  cancelling==-0.02622259641
excess+cancelling==6.421469e-07

This shows that, for some reason, the sum over domains of sum_side_current()
of the problem-interior domain boundaries is not getting cancelled as it should.

…on and initialization.

Now the inflow boundaries have matching received and interpolated-from-received.
Conservation discrepancy down from 1e-2 to 6e-7.