availStart {pcts}

Time of first or last non-NA value

Description

Time of first or last non-NA value.

Usage

availStart(x, any = TRUE)

availEnd(x, any = TRUE)

Arguments

x

a time series or similar object

any

logical flag for multivariate objects. The default TRUE requests the first/last index containing any non-NA value. FALSE requires that all values at the first/last index must be non-NA.

Details

The time is given as a cycle-season pair.

Argument any is meaningful only for multivariate objects. Its name is short for "the first/last index for which any of the values (ie at least one) is non-NA". any = FALSE is taken to mean that the index is the first/last for which all values are non-NA.

The functions can be used together with windows to trim NA's from the beginning and/or end of the data. As an alternative we provide also methods for periodic time series methods for zoo:na.trim, see the examples below.

Value

numeric, length 2

See Also

window

Examples

tipi <- pcts(dataFranses1996[ , "USTotalIPI"])
start(tipi)
end(tipi)
head(tipi)
tail(tipi)

tipi <- window(tipi, start = availStart(tipi), end = availEnd(tipi))
start(tipi)
end(tipi)
plot(tipi)

pcfr <- pcts(dataFranses1996)

pcfr2to4 <- pcfr[2:4]
head(pcfr2to4)
tail(pcfr2to4)
## time of first and last data, can be NA's
start(pcfr2to4) # 1955 Q1
end(pcfr2to4)   # 1991 Q4

## time of first nonNA:
availStart(pcfr[[2]]) # 1960 Q1
availStart(pcfr2to4)  # 1960 Q1

## time of last nonNA:
availEnd(pcfr[[2]])   # 1991 Q4
availEnd(pcfr[[3]])   # 1987 Q4
availEnd(pcfr[[4]])   # 1990 Q4
## but at least one of them is  available for 1991 Q4, so:
availEnd(pcfr2to4)   # 1991 Q4
## this requests the time of the last full record:
availEnd(pcfr2to4, any = FALSE)   # 1987 Q4

pcfr2to4a <- window(pcfr2to4, start = availStart(pcfr2to4), end = availEnd(pcfr2to4))
head(pcfr2to4a)
tail(pcfr2to4a, 20)

## trim NA's from both ends, up to the firsxst/last full record:
pcfr2to4b <- window(pcfr2to4, start = availStart(pcfr2to4, FALSE),
                              end = availEnd(pcfr2to4, FALSE))

## TODO: need a better example here since the first non-NA value for all
##     ts in pcfr2to4 is at the same

## alternatively, use na.trim(), the default for is.na is "any"
pcpres <- window(pcts(presidents), end = c(1972, 4))

availStart(pcpres) # 1945 2
availEnd(pcpres)   # 1972 2

both <- na.trim(pcpres) # same as "both"
identical(na.trim(pcpres), both) # TRUE
head(both, 7)
tail(both)
head(na.trim(pcpres, "left"), 7)
tail(na.trim(pcpres, "right"))

cguk <- pcfr[c("CanadaUnemployment", "GermanyGNP", "UKTotalInvestment")]
availStart(cguk)
availStart(cguk, TRUE) # same

availStart(cguk, FALSE)

availEnd(cguk)
availEnd(cguk, TRUE) # same

availEnd(cguk, FALSE)


na.trim(cguk)
head( na.trim(cguk, sides = "left") )
tail( na.trim(cguk, sides = "right") )

head( na.trim(cguk, sides = "left", is.na = "all") )
tail( na.trim(cguk, sides = "right", is.na = "all") )