is_era_year

Tests whether an object is of class <code>era_year</code> (constructed by <code>era_year()</code>).

Provides a consistent representation of year-based time scales as a
numeric vector with an associated 'era'. There are built-in era definitions
for many year numbering systems used in contemporary and historic calendars
(e.g. Common Era, Islamic 'Hijri' years); year-based time scales used in
archaeology, astronomy, geology, and other palaeosciences (e.g.
Before Present, SI-prefixed 'annus'); and support for arbitrary user-defined
eras. Years can converted from any one era to another using a generalised
transformation function. Methods are also provided for robust casting and
coercion between years and other numeric types, type-stable arithmetic with
years, and pretty-printing in tables.

Joe Roe

Year-Based Time Scales

is_era_year function

<dl><dt>x</dt>
<dd>Object to test.</dd></dl>

Arguments

Validation functions for era_year objects — is_era_year

<dl>

<dt>x</dt>
<dd>Object to test.</dd>

</dl>

is_era_year: Validation functions for `era_year` objects

Description

Usage

Value

Arguments

See Also

Examples