store shocks in namespace --> #760

[sbenthall]

Storing the shock values in a namespace dictionary.

• Tests for new functionality/models or Tests to reproduce the bug-fix in code.
• Updated documentation of features that add new functionality.
• Update CHANGELOG.md with major/minor changes.

[sbenthall]

@mnwhite I wonder if you could help me with this.

I've been able to work out some changes that move the shocks into a namespace -- a dictionary self.shocks on the agent.

I was able to get tests passing on the ConsIndShockModel agent types.

And I was making progress on ConsPrefShockModel and ConsMedShockModel, but then I wanted to make sure I was keeping valid results. So I expanded the test covered to simulated values of cNrmNow (see #802 )

These new tests do not pass.

I can't tell from where I'm sitting whether I should expect different results, maybe because of how the random seeds are drawn, or if I've made a mistake somewhere.

Any ideas?

[sbenthall]

An argument seed = self.RNG.randint(0, 2**31-1) needs to be passed in here:
https://github.com/econ-ark/HARK/blob/master/HARK/ConsumptionSaving/ConsPrefShockModel.py#L116-L118

[sbenthall]

Ok, it looks like the falling ConsPrefShock test was due to my not properly handling the read_shocks issue.
This PR now has that work, partly enabled by the shock history handling from #812
I can now proceed with the other consumption models

[sbenthall]

This PR is now ready to review.
It's passing tests locally.

[sbenthall]

(Whoops--closed by accident! Reopened it)

I request the reviewer pay a little extra attention to initializeSim() in MarkovConsumerType.
I had to add a line there to get things to work.

Otherwise, it's mostly just replacing the exogenous shock Now attribute assignments with dictionary inserts, and likewise for access them

[mnwhite]

SB: You said to merge this first, before #812, right? This looks good to me, but I wanted to be double sure.

[sbenthall]

@mnwhite the other way around. #812 should be, and has been, merged first. this is now good to merge.

[mnwhite]

Glad I asked.