Sampling Frequency

This function identifies the sampling frequency of a zoo object. It is wrapper to the periodicity function of the xts package.

Usage

sfreq(x, min.year = 1800)

Arguments

x: variable of type zoo, xts or ts, with AT LEAST 2 elements, AND with a (sub)hourly, hourly, daily, weekly, monthly, quarterly, or annual (yearly) sampling frequency.
min.year: integer used for a correct identification of the sampling frequency when x is an annual (yearly) time series.

Details

See further details in the periodicity function of the xts package.

Value

Character. Possible values are:
-) minute : indicating that the sampling frequency in x is sub-hourly
-) hourly : indicating that the sampling frequency in x is hourly
-) daily : indicating that the sampling frequency in x is daily
-) weekly : indicating that the sampling frequency in x is weekly
-) monthly : indicating that the sampling frequency in x is monthly
-) quarterly : indicating that the sampling frequency in x is quarterly
-) annual : indicating that the sampling frequency in x is annual

Author

Mauricio Zambrano-Bigiarini, mzb.devel@gmail

Examples

## Ex1: sub-hourly data
## Creating a dummy 15-min zoo object, with 1 as the only value in each time period
dt  <- seq( from=as.POSIXct("2021-06-30 00:15"), to=as.POSIXct("2021-06-30 23:45"), by="15 min" )
ndt <- length(dt)
shr <- zoo( rep(1, ndt), dt)
sfreq(shr)
#> [1] "minute"


## Ex2: hourly data 
## Loading the time series of HOURLY streamflows for the station Karamea at Gorge
data(KarameaAtGorgeQts)
hr <- KarameaAtGorgeQts
sfreq(hr)
#> [1] "hourly"


## Ex3: Daily data
## Loading daily streamflows at the station Oca en Ona (Ebro River basin, Spain)
data(OcaEnOnaQts)
d <- OcaEnOnaQts
sfreq(d)
#> [1] "daily"


## Ex4: Monthly data
m <- daily2monthly(d, FUN=mean, na.rm=TRUE)
sfreq(m)
#> [1] "monthly"


## Ex5: Annual data
a <- daily2annual(d, FUN=mean, na.rm=TRUE, out.fmt="%Y-%m-%d")
sfreq(a)
#> [1] "annual"