Estimation inputs & outputs

[Hana]

I mentioned in my presentation in SF that for us having the same config file for estimation inputs as well as outputs is very inconvenient and has been causing lots of frustrations. Here are the main reasons:

• The config file gets reorganized and reformatted.
• No support of experimentation/documentation by allowing comments (comments get deleted!!!).
• Complicates things for Git which treats it as changed every time somebody runs an estimation.

I looked at the code and it seems straight forward to modify the hedonic/lcm_estimate functions and the fit_from_cfg methods to include an optional argument giving an alternative name of the output yaml file. We will most likely make that modification in our local version of the code.

I was wondering if you guys at Urbansim Inc. would reconsider this design decision and if not what are the advantages to use the same file? Thanks.

[janowicz]

I agree with you about the usefulness of having a separate file for estimation output- for the same reasons you mention. Once you have such an optional argument in place, would be great to issue a pull request to the main UrbanSim repo to further the discussion on this topic.

[Hana]

Hi Eddie, I just submitted two pull requests - it affects both, urbansim_defaults and urbansim. The change allows to define your model for example as follows:

@orca.step('repm_estimate')
def repm_estimate(parcels):
    return utils.hedonic_estimate("repmspec.yaml", ..., out_cfg="repmcoef.yaml")

@orca.step('repm_simulate')
def repm_simulate(parcels):
    return utils.hedonic_simulate("repmcoef.yaml", parcels, ...)

So there is a separate file for the specification and for the estimation results. The same can be done for an LCM. Please fell free to rename the arguments or change whatever is needed.

[janowicz]

Thanks Hana! The pull request on the urbansim repo is merged.

[Hana]

Thanks Eddie! Do you plan to also merge the urbansim_default pull request, so that the change is visible to hedonic_estimate and lcm_estimate?

[janowicz]

I can! I'll take a look. I hadn't used urbansim_defaults in a little while, so was waiting to see if others would chime in