era_year

<code>era_year</code> objects describe the unit used for a year as its length in days.
This value is used in an era definition (<code>era()</code>) to enable conversions
between eras that use different units (with <code>yr_transform()</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

era_year function

<dl><dt>label</dt>
<dd>Character. Name of the year unit.</dd>
<dt>days</dt>
<dd>Numeric. Average length of the year in solar days. Defaults to a
Gregorian year (365.2425 days).</dd></dl>

Arguments

Year units — era_year

<dl>

<dt>label</dt>
<dd>Character. Name of the year unit.</dd>


<dt>days</dt>
<dd>Numeric. Average length of the year in solar days. Defaults to a
Gregorian year (365.2425 days).</dd>

</dl>

era_year: Year units

Description

Usage

Value

Arguments

See Also

Examples