Provide examples for a multi-project workflow

[csadorf]

Original report by Carl Simon Adorf (Bitbucket: csadorf, GitHub: csadorf).

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The example should demonstrate how to integrate multiple projects either directly or via an index.

[bdice]

@csadorf Can you clarify what was meant by "multiple projects"? (Also wow, this issue was created over 3 years ago.)

[csadorf]

What I mean are examples on how to use or link to (potentially aggregated) data from another project as input for a new one.

[bdice]

I'm planning an example requested by @phmalek about machine learning. I am using a data structure for my current research that has multiple projects, with one project for data (which doesn't really change) and one project for different models and their hyperparameters (which is where most of the "operations" happen). I am looking for toy examples of hyperparameter optimization to demonstrate this structure. I may find some good examples that can be adapted from packages like hyperopt.