baseDay: Base Day

In leppott/baytrends: Long Term Water Quality Trend Analysis

Base Day

Description

Computes the base day of the year, a reference value that can be used to group days for the computation of summary statistics. From smwrBase package.

Usage

baseDay(x, numeric = TRUE, year = c("calendar", "water", "climate"))

Arguments

x	a vector of class POSIXt, Dates, or character that represents a date. Missing values are permitted.
numeric	a logical value; TRUE means return the numeric value of the day, FALSE means return a factor.
year	a character string indicating the basis of the factor levels. See Details.

Details

The base day is computed such that all dates have the same reference value regardless of whether the year is a leap year or not. If year is "calendar," then the factor levels or day number begin on January 1; if year is "water," then the factor levels or day number begin on October 1; and if year is "climate," then the factor levels or day number begin on April 1.

Value

An integer value representing the base day number if numeric is TRUE. Otherwise a factor with levels for every day of the year.

Examples

# The default numeric result
baseDay(c("2000-02-29", "2000-03-01", "2001-03-01"))
# The result as a factor
baseDay(c("2000-02-29", "2000-03-01", "2001-03-01"), numeric=FALSE)

leppott/baytrends documentation built on Nov. 2, 2024, 6:42 p.m.