Segmenting climate and environmental data

Description

The function calculates means or sums, or extracts minimum or maximum values of environmental parameters for stem-cyclic phases as defined using cycle_stats.

Usage

climate_seg(env.data, dm.stats, value = c("mean", "min",
            "max", "sum"))

Arguments

Details

The function segments environmental parameters according to the stem-cyclic phases as defined using cycle_stats. Means, sums, and minimum and maximum values can be calculated or extracted.

env.data should cover at least the same period as the dendrometer data used to define the cyclic phases, and should have the same (or a higher) temporal resolution.

Value

The function returns a data.frame with segmented environmental data. The data.frame contains the following columns:

Examples

data(dmED)
dm.gpf <- fill_gaps(dmED)
dm.phase <- phase_def(dm.gpf)
dm.stats <- cycle_stats(dm.gpf, dm.phase)
data(envED)
clim.phase <- climate_seg(envED, dm.stats, value = "mean")

Define stem cycles and calculate statistics for all cyclic phases

Description

The function defines stem cycles from output of phase_def and calculates statistics for complete cycles as well as for the phases of contraction, expansion and stem-radius increment.

Usage

cycle_stats(dm.gpf, dm.phase, sensor = 1, smooth.param = 1)

Arguments

Details

The function uses the output of phase_def to define stem cycles and to calculate statistics for all cyclic phases. These statistics include the timing and duration of each phase, as well as information on stem-size changes. The function works for single dendrometer series, which are defined by the argument sensor.

The function includes a smoothing option (argument smooth.param) particularly for noisy datasets in which outliers may under- or overestimate the minimum and maximum stem size within phases and stem cycles. By default, no smoothing is performed.

Value

The function returns a list with:

• a data.frame named cycleStats containing the following summary statistics:

• a data.frame named cycle.df containing, for all individual records, the following columns:

Author(s)

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

Examples

data(dmCD)
dm.phase <- phase_def(dmCD)
dm.stats <- cycle_stats(dmCD, dm.phase)

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)

Arguments

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.

Value

The function returns:

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

• 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).

Author(s)

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

Examples

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

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

Check the resolution of the data

Description

The function provides the resolution of the dendrometer data.

Usage

dendro.resolution(dm.data, unts = c("secs", "mins", "hours", "days"))

Arguments

Value

The function returns the resolution of the data in the desired unit.

Author(s)

Marko Smiljanic

Examples

data(dmCD, dmHS, dmED)
dendro.resolution(dmCD, unts = "hours")
dendro.resolution(dmHS, unts = "hours")
dendro.resolution(dmED, unts = "mins")

Pre-processed dendrometer data from Camp Daniel, Canada

Description

This dataset presents a pre-processed version of dmCDraw, in which different time variables were converted to a timestamp using code provided in the Import dendrometer data vignette.

Usage

data(dmCD)

Format

A data.frame with a timestamp (%Y-%m-%d %H:%M:%S format) as row names, and the dendrometer series in the first column.

Raw dendrometer data from Camp Daniel, Canada

Description

This dataset presents hourly dendrometer series for a black spruce (Picea mariana (Mill.) BSP) tree from Camp Daniel, Canada, for the year 2008.

Usage

data(dmCDraw)

Format

A data.frame with a dendrometer series and various time variables.

Source

Sergio Rossi

Pre-processed dendrometer data from Eldena, Germany

Description

This dataset presents a pre-processed version of dmEDraw, using code provided in the Import dendrometer data vignette.

Usage

data(dmED)

Format

A data.frame with a timestamp (%Y-%m-%d %H:%M:%S format) as row names, and the two dendrometer series in the first and second column.

Raw dendrometer data from Eldena, Germany

Description

This dataset presents half-hourly dendrometer series for two European beech (Fagus sylvatica L.) trees from the monitoring plot Eldena, Germany, for the year 2015.

Usage

data(dmEDraw)

Format

A data.frame with dendrometer series and a timestamp.

Source

Martin Wilmking

Pre-processed dendrometer data from Hinnensee, Germany

Description

This dataset presents a pre-processed version of dmHSraw, using code provided in the Import dendrometer data vignette.

Usage

data(dmHS)

Format

A data.frame with a timestamp (%Y-%m-%d %H:%M:%S format) as row names, and the dendrometer series in the first column.

Raw dendrometer data from Hinnensee, Germany

Description

This dataset presents half-hourly dendrometer series for a European beech (Fagus sylvatica L.) tree from the monitoring plot Hinnensee, Germany, for the year 2012.

Usage

data(dmHSraw)

Format

A data.frame with a dendrometer series and various time variables.

Source

Sonia Simard

Environmental data from Eldena, Germany

Description

This dataset presents some temperature data from the monitoring plot Eldena, Germany, for the year 2015.

Usage

data(envED)

Format

A data.frame with a timestamp (%Y-%m-%d %H:%M:%S format) as row names, and air and soil temperature parameters in columns.

Source

Martin Wilmking

Fill gaps in dendrometer series

Description

The function fills gaps in a data.frame with dendrometer series using an ARMA model (cf. Deslauriers et al. 2011), and is designed for single growing seasons. The function is able to fill gaps of short duration (i.e. several hours), but cannot sensibly handle long gaps.

Usage

fill_gaps(dm.data, Hz = 0.01, season = FALSE)

Arguments

Details

The function uses auto.arima to fill missing records. The non-seasonal part of the model is specified by the three integer components: the AR order p, the degree of differencing d, and the MA order q. For the seasonal part of the model, the period parameter is set equal to the number of daily measurements observed in the dendrometer data. The output of the ARMA model is smoothed using smooth.Pspline. The smoothing parameter Hz can be adjusted; defaults to 0.01.

The function is designed for single growing seasons, amongst others because ARMA-based gap-filling routines will then perform best (i.e. ARMA parameters might be distinct for individual growing seasons). To allow the usage of fill_gaps for datasets from the Southern Hemisphere, the input data may contain two consecutive calendar years.

Value

The function returns a data.frame with gap-filled dendrometer series.

Author(s)

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

References

Deslauriers, A., Rossi, S., Turcotte, A., Morin, H. and Krause, C. (2011) A three-step procedure in SAS to analyze the time series from automatic dendrometers. Dendrochronologia 29: 151-161.

Examples

data(dmCD)

# creating some artificial gaps (for demonstration purposes):
dmCD[c(873:877,985:990),1] <- NA

# slow, as also seasonal models are checked, but best possible gap-filling:
dm.gpf <- fill_gaps(dmCD, Hz = 0.01, season = TRUE)

Plot gap-filled dendrometer series

Description

The function creates a plot with gap-filled and original dendrometer series.

Usage

fill_plot(dm.data, dm.gpf, sensor = 1, year = NULL,
          period = NULL)

Arguments

Details

The function creates a plot showing the gap-filling results for a single dendrometer series over a specified time window. Although the function is intended to plot short time periods (within a growing season), it can plot two calendar years at maximum (e.g., 2014-2015), thereby allowing the visualization of a complete growing season at the Southern Hemisphere as well.

Value

Plot.

Author(s)

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

Examples

data(dmCD)
## creating some artificial gaps (for demonstration purposes):
dmCD[c(873:877,985:990),1] <- NA
dm.gpf <- fill_gaps(dmCD, Hz = 0.01)
fill_plot(dmCD, dm.gpf, period = c(137,144))

Check input data

Description

The function checks whether the input data is in the required format, as described in the Import dendrometer data vignette.

Usage

is.dendro(dm.data)

Arguments

Value

The function returns TRUE if the input data is valid and FALSE otherwise. In the latter case, specific error messages are given as well.

Author(s)

Ernst van der Maaten, Marieke van der Maaten-Theunissen and Marko Smiljanic.

Examples

data(dmCD, dmHS, dmED)
is.dendro(dmCD)
is.dendro(dmHS)
is.dendro(dmED)

Define stem-cyclic phases

Description

The function identifies and assigns each timestamp to one of the three distinct phases of contraction, expansion and stem-radius increment (Deslauriers et al. 2011) for dendrometer series from a data.frame with gap-free dendrometer data.

Usage

phase_def(dm.gpf, resolution = dendro.resolution(dm.gpf),
          shapeSensitivity = 0.6, minmaxDist = 0.2, minmaxSD = 2,
          radialIncrease = "max")

Arguments

Details

The function defines the stem-cyclic phases of contraction, expansion, and stem-radius increment, as described in Deslauriers et al. (2011). The function is a more robust version of the original SAS routine, as its architecture allows to handle noisy data as well.

First, the function searches for minimum and maximum points within a daily time window as specified by shapeSensitivity. Then, the original dendrometer series are offset by (1 - shapeSensitivity) / 2 in both directions to assure whether the identified extrema are indeed the extrema of cyclic phases. A comparison between the original and offset series allows to select all appropriate minimum and maximum values.

The arguments minmaxDist and minmaxSD specify the temporal distance and the minimum difference between consecutive minimum and maximum points (i.e. in x and y direction), respectively. The argument radialIncrease determines from which moment on data points should be assigned to the stem-radius increment phase: when points are continuously above the previous maximum ("max"), when a single data point is above the previous maximum ("min"), or right in between "min" and "max" ("mid").

Value

The function returns a data.frame with numbers indicating the different stem-cyclic phases: (1) contraction, (2) expansion, (3) stem-radius increment for each timestamp.

Author(s)

Marko Smiljanic

References

Deslauriers, A., Rossi, S., Turcotte, A., Morin, H. and Krause, C. (2011) A three-step procedure in SAS to analyze the time series from automatic dendrometers. Dendrochronologia 29: 151-161.

Examples

data(dmCD)
dm.phase <- phase_def(dmCD)

Plot stem-cyclic phases

Description

The function creates a plot showing the three distinct phases of contraction, expansion and stem-radius increment (Deslauriers et al. 2011) for dendrometer series from a data.frame as produced by phase_def.

Usage

phase_plot(dm.gpf, dm.phase, sensor = NULL, period = NULL, colPhases = NULL, ...)

Arguments

Details

The function plots phases of contraction, expansion and stem-radius increment along (one or more) dendrometer series. If more series are plotted (default), colors for the different lines can be defined using the col argument for graphical devices (see par). Note: if there are not enough custom colors, the function will repeat the last one used. If no colors are defined, the current palette will be used.

The time axis will be automatically labeled depending upon the length of the dendrometer series. If period is specified using a numeric, DOY values are displayed on the x-axis. In case a character of two time stamps is provided, axis labeling will be as follows: if series are longer than 120 days, years and months will be shown. If the length is between 30 and 120 days, months and days, and below 30 days, months, days and hours are displayed.

Value

Plot showing stem-cyclic phases on dendrometer series.

Author(s)

Marko Smiljanic

References

Deslauriers, A., Rossi, S., Turcotte, A., Morin, H. and Krause, C. (2011) A three-step procedure in SAS to analyze the time series from automatic dendrometers. Dendrochronologia 29: 151-161.

Examples

data(dmCD)
dm.phase <- phase_def(dmCD)
phase_plot(dmCD, dm.phase)

# zoom in on the dendrometer series
phase_plot(dmCD, dm.phase, period = c(133, 142))

# customization options
phase_plot(dmCD, dm.phase, period = c("2008-05-12", "2008-05-22"),
           colPhases = c("green", "cyan", "orange"),
           pch = 4, main = "Dendrometer", ylab = "Values")

# specific sensors may be selected as follows:


data(dmED)
dm.gpf <- fill_gaps(dmED)
dm.phase <- phase_def(dm.gpf)
phase_plot(dm.gpf, dm.phase, sensor = 1)
phase_plot(dm.gpf, dm.phase, sensor = c(2,1))
phase_plot(dm.gpf, dm.phase, sensor = "Beech03")
phase_plot(dm.gpf, dm.phase, sensor = c("Beech03", "Beech04"))