tind-package: A Common Representation of Time Indices of Different Types
In tind: A Common Representation of Time Indices of Different Types

tind-package

R Documentation

A Common Representation of Time Indices of Different Types

Description

The goal of tind project is to provide users with a single class capable of representing time indices of different types. Currently, these include: years, quarters, months, ISO 8601 weeks, dates, time of day, date-time, and arbitrary integer/numeric indices. tind provides a unified interface and a collection of methods, which can be used with all supported index types.

The package provides an extensive collection of functions for calendrical computations (including business applications), index conversions, index parsing, and other operations. Examples of use of tind functions and methods can be found in their documentation and in package vignettes.

All routines have been optimised for speed in order to facilitate computations on large datasets.

Details

Options Controlling tind Behaviour

tind.abbr.year.start is a number in range 0–99 determining how two-digit years are interpreted during parsing. By default (69), two-digit numbers smaller than 69 are interpreted as years in 2000s and equal or greater than 69 as years in 1900s.

tind.warn.diff.tz is a logical value (TRUE by default) determining whether warnings should be raised when performing computations involving date-time indices with different time zone attributes.

Implementation

The code structure is hierarchical by design. The first layer consists of low-level C and R functions working with particular time index types and converting between them. The second layer consists of exported (user-accessible) functions, which are responsible for argument checks and dispatching to the 1st layer functions.

Computations with tind for types other than date-time are implemented in C from scratch. Many algorithms were taken from Calendar FAQ by Claus Tøndering. For date-time computations, tind partially relies on base R infrastructure (POSIXlt class), that is on conversion as.POSIXlt.numeric.