`climpred.classes.HindcastEnsemble.bootstrap` dim `member` and `init` simultaneously

[zmli-666]

Could the HindcastEnsemble.bootstrapresample for "member" and "init" in dim simultaneously? And how?

[aaronspring]

Thank you for considering climpred and raising this issue @zmli-666.

Bootstrapping / resampling along both dimensions simultaneously isn't implemented (yet). It could be implemented by doing first the init resampling and then internally a member resampling on top of that.

PR welcome 😃

[aaronspring]

Could explore https://github.com/dougiesquire/xbootstrap

[aaronspring]

played a bit around with xbootstrap: https://gist.github.com/aaronspring/471e70f787aef6689825182e794421fb