Gauge exactly at boundary produces no output

[ketch]

In at least one example I've seen, placing a gauge exactly at a domain boundary leads to PyClaw silently producing no output for that gauge.

[mandli]

We could switch to the same logic in AMRClaw and GeoClaw for gauges which circumvents this problem.

[ketch]

@mandli Thanks for the suggestion. In those codes, do you do some kind of interpolation to obtain pointwise gauge values, or do you just use the nearest cell center?

Where is the logic you're referring to, in the code?

[mandli]

The primary logic starts at

https://github.com/clawpack/amrclaw/blob/master/src/2d/gauges_module.f90#L398

and uses bilinear interpolation. There is a bit of complexity due to AMR that we would not need to worry about.