A C/C++ based package for advanced data transformation and 
    statistical computing in R that is extremely fast, flexible and 
    parsimonious to code with, class-agnostic and programmer friendly. 
    It is well integrated with base R, 'dplyr' / (grouped) 'tibble', 
    'data.table' and 'plm' (panel-series and data frames), and non-
    destructively handles other matrix or data frame based classes (such as 
    'ts', 'xts' / 'zoo', 'timeSeries', 'tsibble', 'sf' data frames etc.)
    --- Key Features: ---
    (1) Advanced statistical programming: A full set of fast statistical functions 
        supporting grouped and weighted computations on vectors, matrices and 
        data frames. Fast and programmable grouping, ordering, unique values / rows, 
        factor generation and interactions. Fast and flexible functions for data 
        manipulation and data object conversions.
    (2) Advanced aggregation: Fast and easy multi-data-type, multi-function, 
        weighted, parallelized and fully customized data aggregation.
    (3) Advanced transformations: Fast row / column arithmetic, (grouped) replacing 
        and sweeping out of statistics, (grouped, weighted) scaling / standardizing, 
        between (averaging) and (quasi-)within (centering / demeaning) transformations, 
        higher-dimensional centering (i.e. multiple fixed effects transformations), 
        linear prediction / partialling-out, linear model fitting and testing.
    (4) Advanced time-computations: Fast (sequences of) lags / leads, and 
        (lagged / leaded, iterated, quasi-, log-) differences and (compounded) 
        growth rates on (unordered, irregular) time series and panel data. 
        Multivariate auto-, partial- and cross-correlation functions for panel data. 
        Panel data to (ts-)array conversions.
    (5) List processing: (Recursive) list search / identification, splitting, 
        extraction / subsetting, data-apply, and generalized recursive 
        row-binding / unlisting in 2D.
    (6) Advanced data exploration: Fast (grouped, weighted, panel-decomposed) 
        summary statistics for complex multilevel / panel data.