piar: Price Index Aggregation in R

• The vignette has been re-written, split into small examples that cover more topics, and should be easier to follow.

Improvements

• Added set_levels(), set_time(), and set_weights() to make it easier to replace levels, times, and weights with pipes.

• contrib(index) <- value can now be used to replace product contributions. The alias set_contrib() is easier to use with pipes.

• elementary_index() is now an alias for elemental_index() as this is more common in the literature.

• aggregate() can now use two aggregation structures to make a superlative index.

• cut(aggregation_structure) can be used cut off the bottom/top of an aggregation structure. Works in conjunction with set_contrib_from_index() to calculate index-level contributions.

• Aggregation structures now preserve the names of their levels to work with cut(). This means that as.data.frame(aggregation_structure) can produce different column names.

• as.data.frame(index) gets an option to make a list-column of percent-change contributions. as_index(data.frame) gets an analogous option to add contributions in a table to an index.

• as.ts(index) can now be used to turn an index into a regular time series and as_index(ts) can turn a time series into an index object.

• split_classification() gives another way to generate an aggregation structure from a character vector.

Bug fixes

• as.data.frame() methods now respect the signature of the generic. This allows row names to be set and prevents superfluous warnings when trying to use data.frame(); e.g., with write.csv() (#34).

• Subscripting an index object with a length 0 vector is no longer an error (#48).