Merge Multiple Spiketrains

[Kleinjohann]

Addresses #632

I extended the spiketrain.merge function to an arbitrary number of arguments with the interface def merge(self, *others) in order not to change anything for the case of just merging two spiketrains as suggested in #632 (comment)

I similarly extended BaseNeo.merge and BaseNeo.merge_annotations in order to be able to merge the annotations correctly.

[pep8speaks]

Hello @Kleinjohann! Thanks for updating this PR. We checked the lines you've touched for PEP 8 issues, and found:

There are currently no PEP 8 issues detected in this Pull Request. Cheers! 🍻

Comment last updated at 2020-02-07 08:51:12 UTC

[Kleinjohann]

I'm not too sure how merging SpikeTrainProxies is supposed to work, should it just not work and raise an error? Or should it load the SpikeTrains automatically? Or should it return a ProxyObject which will return the merged SpikeTrain when one calls its load function?

[samuelgarcia]

Intuitivelly I would say "load automatically" then merge.
With this we could merge a list that mix SpikeTrain and SpikeTrainProxy.

[Kleinjohann]

I incorporated the changes @apdavison requested and resolved the conflicts.
Merging multiple SpikeTrain objects could also be interesting in the context of the new SpikeTrainList in #588. Something like SpikeTrainList.as_single_spiketrain would cover most of the use cases I am using this for.

[JuliaSprenger]

Hi @Kleinjohann. Thank for the fixes. To me the PR looks fine. The only issue not solved is if SpiketrainProxyObjects should be automagically loaded for merging as suggested by @samuelgarcia.

[Kleinjohann]

@JuliaSprenger I went with @apdavison 's remark in #652 (comment) and changed the behaviour to returning an error instead of loading automagically.

[JuliaSprenger]

Ok, then we can leave the automagic loading of data discussion for another issue, since it's a rather fundamental one.