ensemble models

[dsweber2]

closes #37, #4, and now #21
A PR to add ensembles. Initially this is just adding one that averages the quantiles of the forecasts handed to it (using a user-specified function, which is currently targeting median and mean), I'm currently working on adding in the proper targets and naming scheme, which is why this is a draft

[dshemetov]

initial review, will do another pass after merge

[dsweber2]

@nmdefries I'm having some difficulties getting the ensembles to plot in the shiny dashboard; hypothetically it should be just the same data format as the other forecasters, but it's throwing errors. Looking at e.g. tar_read(score_ultrafaultless.leading) it's a tibble of size 11,016x21, and not 4, but the dashboard is throwing this error. Do we have a collection of unit tests for the plotting functions or some other way of debugging borked behavior?

Warning: Error in mutate: ℹ In argument: `forecaster = gsub(...)`.
Caused by error:
! `forecaster` must be size 11016 or 1, not 4.
  146: <Anonymous>
  145: signalCondition
  144: signal_abort
  143: abort
  142: <Anonymous>
  141: signalCondition
  140: signal_abort
  139: abort
  138: dplyr_internal_error
  137: eval
  136: mask$eval_all_mutate
  135: mutate_col
  133: mutate_cols
  132: mutate.data.frame
  131: mutate
  121: list2
  120: bind_rows
  118: <reactive:filtered_scorecards_reactive> [/home/dsweber/allHail/delphi/exploration-tooling/app.R#141]
  102: filtered_scorecards_reactive
  101: renderPlotly [/home/dsweber/allHail/delphi/exploration-tooling/app.R#152]
  100: func
   97: shinyRenderWidget
   96: func
   83: renderFunc
   82: output$main_plot
    1: runApp
Input to asJSON(keep_vec_names=TRUE) is a named vector. In a future version of jsonlite, this option will not be supported, and named vectors will be translated into arrays instead of objects. If you want JSON object output, please use a named list instead. See ?toJSON.

[dsweber2]

@dshemetov with Nat's fix of the dashboard, I think this is finally ready for final review

[dshemetov]

Looks good overall, we probably need to get this PR in and iterate instead of polishing it for more weeks, but I made some comments here and there.

[dsweber2]

If you want to merge and get an actual largescale run going on mentat over the weekend that would be awesome. Kinda wish there were a good mechanism for migrating review items to issues, but there's this: #70.

[dshemetov]

An issue with a linkback works!