Sub-hourly -> Hourly

Generic function for transforming a sub-HOURLY time series into an HOURLY one

Usage

subhourly2hourly(x, ...)

# Default S3 method
subhourly2hourly(x, FUN, na.rm=TRUE, na.rm.max=0, ...)

# S3 method for class 'zoo'
subhourly2hourly(x, FUN, na.rm=TRUE, na.rm.max=0, tz, ...)

# S3 method for class 'data.frame'
subhourly2hourly(x, FUN, na.rm=TRUE, na.rm.max=0,
           dates=1, date.fmt="%Y-%m-%d %H:%M:%S", out.fmt="zoo", 
           verbose= TRUE, ...)

# S3 method for class 'matrix'
subhourly2hourly(x, FUN, na.rm=TRUE, na.rm.max=0,
           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.

FUN

Function that have to be applied for transforming from sub-hourly to hourly 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

na.rm.max

Numeric in [0, 1]. It is used to define the maximum percentage of missing values allowed in each hour to keep the hourly aggregated value in the output object of this function. In other words, if the percentage of missing values in a given hour is larger than na.rm.max the corresponding hourly value will be NA.

tz

character, with the specification of the time zone used for x. System-specific (see time zones), but "" is the current time zone, and "GMT" is UTC (Universal Time, Coordinated). See Sys.timezone and as.POSIXct.

If tz is missing (the default), it is automatically set to the time zone used in time(x).

If tz is provided, it forces time(x) to be in the tome zone specified by tz, without modifying the the values (hours, minutes, seconds, etc).

A list of valid time zones can be obtained by calling the base function OlsonNames().

This argument can be used when working with sub-daily zoo objects to force using time zones other than the local time zone for x. It should be used with caution, being well aware of the time zone of the data. See examples.

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 15-min time sequence and counting its length
dt  <- seq( from=as.POSIXct("2021-06-30 00:15"), to=as.POSIXct("2021-06-30 23:45"), by="15 min" )
ndt <- length(dt)

## Creating a dummy 15-min zoo object, with 1 as the only value in each time period
x <- zoo( rep(1, ndt), dt)


## sub-hourly to hourly
h1 <- subhourly2hourly(x, FUN=sum, na.rm=TRUE)

## Aggregation of 3 sub-hourly ts (i.e., a zoo matrix) into an hourly one
X  <- cbind(x, x, x)
h2 <- subhourly2hourly(X, FUN=sum, na.rm=TRUE)

Usage

Arguments

Value

Author

See also

Examples