Ecfun (version 0.3-2)

countByYear: Allocate a total by year

Description

Allocate total to countByYear for a constant count per day between start and end.

Usage

countByYear(start, end, total=1)

Value

a numeric vector whose sum is

total with names for all the years between

start and end

Arguments

start, end

objects of class "Date" specifying the start, end, respectively, of the event

total

A number to be allocated by year in proportion to the number of days in the event each year.

Author

Spencer Graves

Examples

##
## 1.  All in one year
##
start73 <- as.Date('1973-01-22')
tst1 <- countByYear(start73, start73+99, 123)

# check 
tst1. <- 123
names(tst1.) <- 1973
stopifnot(
all.equal(tst1, tst1.)
)

##
## 2.  Two years 
##
tst2 <- countByYear(start73, start73+365, 123) 

# check 
dur <- 366
days1 <- (365-21)
days2 <- 22
tst2. <- 123 * c(days1, days2)/dur 
names(tst2.) <- 1973:1974 
stopifnot(
all.equal(tst2, tst2.)
)

##
## 3.  Ten years 
## 
tst10 <- countByYear(start73, start73+10*365.2, 123)

# check 
days <- (c(rep(c(rep(365, 3), 366), length=10), 0)
         + c(-21, rep(0, 9), 22) )
tst10. <- 123 * days/(10*365.2+1) 
names(tst10.) <- 1973:1983 

stopifnot(
all.equal(tst10, tst10.)
)