date2timeperiod: Assign dates to time periods

In BiologicalRecordsCentre/sparta: Trend Analysis for Unstructured Data

Assign dates to time periods

Description

This function assigns dates to timeperiods a nessecary step for methods that use time periods rather than dates, such as Frescalo and Telfer

Usage

date2timeperiod(Date, time_periods)

Arguments

Date	Either a vector of dates or a 2 column data.frame where the first column is the start date and the second column is the end date.
time_periods	A data.frame with two columns, the first column gives the start year of each time period and the second column gives the end year. These year ranges are inclusive.

Value

A vector, the same length as date giving the time periods. Time period 1 is the time period with the earliest start year, 2 with the second earliest start year and so on. If the dates don't fit in a time period or overlap a time period they are given an NA value

Examples

# Create data
n <- 15000 #size of dataset
nyr <- 20 # number of years in data
nSamples <- 100 # set number of dates
nSites <- 50 # set number of sites

# Create somes dates
first <- as.Date(strptime("1980/01/01", "%Y/%m/%d")) 
last <- as.Date(strptime(paste(1980+(nyr-1),"/12/31", sep=''), "%Y/%m/%d")) 
dt <- last-first 
Date <- first + (runif(nSamples)*dt)

# Create time periods dataframe
time_periods <- data.frame(start=c(1980,1990),end=c(1989,1999))

# Create time periods column using a vector
tps <- date2timeperiod(Date = Date, time_periods = time_periods) 

# Create time periods column using a data.frame
tps <- date2timeperiod(Date = data.frame(start = Date, end = (Date+100)),
                       time_periods = time_periods) 

BiologicalRecordsCentre/sparta documentation built on April 22, 2024, 2:34 p.m.