dendrometeR (version 1.1.1)

daily_stats: Calculate daily statistics for dendrometer and environmental data

Description

The function calculates various daily statistics for dendrometer and environmental data. It either returns multiple statistics for individual sensors, or a single statistic for multiple sensors.

Usage

daily_stats(dm.data, sensor = 1, value = c("mean", "min",
            "max", "sum"), smooth.param = 1)

Value

The function returns:

• for sensor is numeric, a data.frame containing the following columns:

dmID

dendrometer ID.

date

timestamp in %Y-%m-%d format.

DOY

day of year.

min

minimum daily stem size.

mean

mean daily stem size.

max

maximum daily stem size.

amplitude

amplitude of daily stem-size changes (i.e. max - min).

time_min

timestamp indicating the timing of the minimum.

time_max

timestamp indicating the timing of the maximum.

• for sensor is "ALL":

a data.frame with a timestamp (%Y-%m-%d) as row names, and processed dendrometer or environmental data in columns (i.e. mean, minimum, maximum or sum).

Arguments

dm.data

a data.frame with a timestamp (%Y-%m-%d %H:%M:%S format) as row names, and dendrometer series in columns. Output as created using code from the Import dendrometer data vignette, or gap-filled dendrometer series as produced by fill_gaps. Environmental data can be specified as well, and should be formatted as dendrometer data.

sensor

a numeric or character string specifying the sensor(s) to be used in the function. Defaults to 1 (first column of data.frame). If "ALL" is specified, a single value will be calculated or extracted for all series in the data.frame.

value

a character string of "mean", "min", "max" or "sum", specifying the daily statistic to be calculated or extracted. Optional argument for sensor = "ALL", defaults to "mean". Argument matching is performed.

smooth.param

a numeric specifying the degree of smoothing. Defaults to 1 (no smoothing). In case smoothing is applied, series should be gap-free or gap-filled.

Author

Olivier Bouriaud, Ernst van der Maaten and Marieke van der Maaten-Theunissen.

Details

The function calculates various daily statistics for dendrometer and environmental data. For sensor is numeric, the function returns multiple statistics for a single sensor. For sensor = "ALL", the function returns a single statistic (i.e. "mean", "min", "max" or "sum") for all columns of the data.frame, whereby "sum" is particularly relevant for environmental parameters like precipitation.

The function includes a smoothing option (argument smooth.param) particularly for noisy datasets in which outliers may under- or overestimate minimum and maximum stem sizes within days. By default, no smoothing is performed. Smoothing requires gap-free series.

Examples

data(dmCD)
dm.daily <- daily_stats(dmCD, sensor = 1)

data(dmED)
dm.daily <- daily_stats(dmED, sensor = "ALL", value = "max")