agg.fluxes {gasfluxes}

Accumulation of fluxes

Description

Aggregate a time series of fluxes to a cummulative flux value.

Usage

agg.fluxes(fluxes, datetimes, timeunit = "hours")

Arguments

fluxes

flux values

datetimes

datetime values (POSIXct or POSIXlt)

timeunit

the unit of time (denominator of the flux unit), supported are the explicit units supported by difftime

Details

The function uses linear interpolation. The unit of the cumulative flux is [fluxes] * timeunit. NA values are removed and values sorted according to time order. If less then two non-NA value pairs are provided, NA is returned for the cumlative flux.

Value

A one-row data.frame with columns

flux

the cumulative flux

from

the start of the cumulation period

to

the end of the cumulation period

The return value being a data.frame is useful, when the function is used for "split-apply-combine" type operations to calculate groupwise cumulated values, e.g., using package data.table.

Examples

#Some random example data
datetimes <- Sys.time() + (1:20)/2*24*3600
set.seed(42)
fluxes <- rlnorm(20, 5)
agg.fluxes(fluxes, datetimes)