Sub-hourly -> n-minutes

Generic function for aggregating a sub-hourly time series into a "n-minutes' one.

Usage

subhourly2nminutes(x, ...)

# S3 method for default
subhourly2nminutes(x, nminutes, FUN, na.rm=TRUE, 
                                     from=start(x), to=end(x), ...)

# S3 method for zoo
subhourly2nminutes(x, nminutes, FUN, na.rm=TRUE, 
                                 from=start(x), to=end(x), ...)

# S3 method for data.frame
subhourly2nminutes(x, nminutes, FUN, na.rm=TRUE, 
        from=start(x), to=end(x), dates=1, date.fmt="%Y-%m-%d %H:%M:%S", 
        out.fmt="zoo", verbose= TRUE, ...)

# S3 method for matrix
subhourly2nminutes(x, nminutes, FUN, na.rm=TRUE, 
        from=start(x), to=end(x), dates=1, date.fmt="%Y-%m-%d %H:%M:%S", 
        out.fmt="zoo", verbose= TRUE, ...)

Arguments

x: zoo, data.frame or matrix object, with sub-hourly time series.
Measurements at several gauging stations can be stored in a data.frame or matrix object, and in that case, each column of x represent the time series measured in each gauging station, and the column names of x represent the ID of each station.
nminutes: numeric, defining the amount of minutes to be used for aggregating x. nminutes must be larger than the amount of minutes between each x value (computed as time(x)[2]-time(x)[1]).
FUN: Function that have to be applied for aggregating from sub-hourly into n-minutes time step. (e.g., for precipitation FUN=sum and for temperature and streamflow ts, FUN=mean).
na.rm: Logical. Should missing values be removed?
-) TRUE : the hourly values are computed considering only those values different from NA
-) FALSE: if there is AT LEAST one NA sub-hourly value within a day, the corresponding hourly value(s) will be NA as well
from: POSIX object indicating the starting time used to carry out the temporal aggregation.
When from > start(x) then x is cut in time to the starting DateTime defined by from.
When from < start(x) then x is extended backward with NAs to the starting DateTime defined by from.
to: POSIX object indicating the ending time used to carry out the temporal aggregation.
When to < end(x) then x is cut in time to the ending DateTime defined by to.
When to > end(x) then x is extended forward with NAs to the ending DateTime defined by from.
dates: numeric, factor, POSIXct or POSIXt object indicating how to obtain the dates and times for each column of x (e.g., gauging station)
If dates is a number, it indicates the index of the column in x that stores the date and times
If dates is a factor, it is converted into POSIXct class, using the date format specified by date.fmt
If dates is already of POSIXct or POSIXt class, the code verifies that the number of elements on it be equal to the number of elements in x
date.fmt: character indicating the format in which the dates are stored in dates, By default date.fmt=%Y-%m-%d %H:%M:%S. See format in as.Date.
ONLY required when class(dates)=="factor" or class(dates)=="numeric".
out.fmt: OPTIONAL. Only used when x is a matrix or data.frame object /cr character, for selecting if the result will be a matrix/data.frame or a zoo object. Valid values are: numeric, zoo (default)
verbose: logical; if TRUE, progress messages are printed
...: further arguments passed to or from other methods.

Value

a zoo object with hourly time series

Author

Mauricio Zambrano-Bigiarini, mzb.devel@gmail

Examples

## Creating a 5-min time sequence and counting its length
dt  <- seq( from=as.POSIXct("2021-06-30 00:00"), to=as.POSIXct("2021-06-30 23:55"), by="5 min" )
ndt <- length(dt)

## Creating a dummy 5-min zoo object, with 1 as the only value in each time period
x <- zoo( rep(1, ndt), dt)


## Aggregation from 5-minute single ts into 10-minute ts
h1 <- subhourly2nminutes(x, nminutes= 10, FUN=sum, na.rm=TRUE)

## Aggregation of 3 ts with 5-minute time frequency (i.e., a zoo matrix) 
## into a 30-minute zoo object.
X  <- cbind(x, x, x)
h2 <- subhourly2nminutes(X, nminutes= 30, FUN=sum, na.rm=TRUE)

Usage

Arguments

Value

Author

See also

Examples