@jdammers I agree this is the best way to check. This is actually what `assert_allclose` does, it makes sure that `max(abs(rel_diff)) < rtol` (thus checking the `max` and `min` simultaneously), but it also adds the functionality that it will "pass" points with `abs(matrix1-maxtrix2) < atol` so that small (near-zero) values can be ignored. Thus the `rtol=1e-4` means that any single point with more than a 0.01% difference will trigger an error, unless the points have less than 1e-7 absolute difference (which is fairly small given the types of values in the variables tested here, which are either unit normals or positions in meters).

Note that the comparisons on these lines (that @dengemann commented on) don't actually cover the forward solution itself, which is stored in `fwd['sol']['data']`. See lines 54 and 59, below, for those comparisons, where tolerances of 0.001% (MEG) and 0.1% (EEG) are used.

@dengemann I know about those residual print statements, I'd like to leave them in. They don't actually print during standard tests because `nose` catches `stdout` (thus only printing when there's a failure), and they make it *much* easier to debug when a test does fail.