collapse provides the following functions to work with time-dependent data:
flag, and the lag- and lead- operators L and F are S3 generics to efficiently compute sequences of lags and leads on ordered or unordered time-series and panel data.
fdiff, fgrowth, and the operators D, Dlog and G are S3 generics to efficiently compute sequences of suitably lagged / leaded and iterated differences, log-differences and growth rates on ordered or unordered time-series and panel data. fdiff/D/Dlog can also compute quasi-differences of the form \(x_t - \rho x_{t-1}\) or \(log(x_t) - \rho log(x_{t-1})\) for log-differences.
psmat is an S3 generic to efficiently convert panel-vectors or plm::pseries and data.frame's or plm::pdata.frame's to panel-series matrices and 3D arrays, respectively.
psacf, pspacf and psccf are S3 generics to compute estimates of the auto-, partial auto- and cross- correlation or covariance functions for panel-vectors or plm::pseries, and multivariate versions for data.frame's or plm::pdata.frame's.
| S3 Generic | Methods | Description | ||
| flag/L/F | default, matrix, data.frame, pseries, pdata.frame, grouped_df | compute (sequences of) lags and leads | ||
| fdiff/D/Dlog | default, matrix, data.frame, pseries, pdata.frame, grouped_df | compute (sequences of lagged / leaded and iterated) (quasi-)differences or (quasi-)log-differences | ||
| fgrowth/G | default, matrix, data.frame, pseries, pdata.frame, grouped_df | compute (sequences of lagged / leaded and iterated) growth rates (exact or log-differences, in percentage terms). | ||
| psmat | default, pseries, data.frame, pdata.frame | convert panel-data to matrix / array | ||
| psacf | default, pseries, data.frame, pdata.frame | compute ACF on panel-data | ||
| pspacf | default, pseries, data.frame, pdata.frame | compute PACF on panel-data |