HessianMatrix.calculateMatrix() returns all zeros

[ctrueden]

Starting with 0.11.0, the HessianMatrix.calculateMatrix() call returns all zeros, in cases where 0.10.0 and earlier returned non-zero results. See this gist for a minimal example.

CC: @maarzt @tpietzsch

[ctrueden]

Note that this issue affects the tubeness op.

[StephanPreibisch]

I also think there is something wrong with it ... needed to reimplement it for my recent project since the results didn’t yield correct eigenvectors after eigenvaluedecomposition - or I misused it somehow. Sorry, didn’t have time to make an example, I’ll show you in Heidelberg ... we can try together

[tpietzsch]

The only thing that changed between these releases is the new Gauss implementation by @maarzt.
Something must be wrong with that. Maybe it's computing intermediate results in the wrong type?
@maarzt can you investigate please?

Quick workaround would be to go back to previous Gauss implementation. (But because nothing else changed, we can also just go back to 0.10.0 downstream...)

[maarzt]

The problem was caused, by the ExecuterService used (newCachedThreadPool). When you ask it, for the number of threads it uses, it returns Integer.MAX_VALUE. The new gauss implementation does so, and fails when it wants to distributes task to Integer.MAX_VALUE threads. Number overflow etc...

@tpietzsch the linked PR fixes the problem: #78

[tpietzsch]

Great, thank you @maarzt!
I'm releasing 0.11.1 now.

[ctrueden]

Thanks guys!