subhourly2nminutes: Sub-hourly -> n-minutes
In hydroTSM: Time Series Management and Analysis for Hydrological Modelling

subhourly2nminutes

R Documentation

Sub-hourly -> n-minutes

Description

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

Usage

subhourly2nminutes(x, ...)

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

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

## S3 method for class '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 class '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(s)

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)

hydroTSM documentation built on Nov. 4, 2024, 5:07 p.m.