This function labels multi-year observations with unique treatments, i.e. the same experiment, location, experimental vs control comparison, product and outcome.

ExtractMYOs(Data)

Arguments

Data

A prepared (ERA) dataset, see the ERA.Prepare function.

Prac

The column name of the variable in Data that describes the practice. Use this parameter to choose different levels of the practice hierarchy. Default = PrName (Practice).

Out.Codes

A vector of outcome codes to consider in the analysis. Default = 101 (Crop Yield).

MinYear

An integer value for the minimum length of a MYO sequence. Sequences with fewer growing season than this number are excluded from analysis. Default = 3.

Value

A list of two data.tables Risk.Means & Risk.Diff, the difference between these is described under the Details section. Output fields:

  • UID = a unique identifier based on the field Outcome,Practice,Practice.Base,Code,ID,Site.ID,EU,T.Descrip,C.Descrip,T.NI,T.NO,C.NI,C.NO,Tree,Variety,Diversity, and Rep.

  • N.Years= the number of unique growing seasons reported for a value of UID.

  • N.Obs = the total number of observation for a value of UID.

Details

A identifier UID is given to "unique" treatment x outcome x product combinations and the number of unique growing seasons N.Years and total number of observations N.Obs is calculated for each UID is calculated. If N.Obs > N.Years this indicates that one or more ERA practices varies, but this is not captured in the ERA dataset. In these unusual circumstances we suggest averaging data for the UID across seasons. This situation may arise where there are levels to an ERA practice such as different amounts of mulch application, but these were not captured in the the Treatment description. The ERA team will be working to solve these issues in a future release.