Package 'STICr'

apply_calibration

Description

This function takes the cleaned data frame generated by tidy_hobo_data and the fitted model object generated by get_calibration. It outputs a data frame with the same columns as the input, plus a calibrated specific conductivity column called SpC.

Usage

apply_calibration(stic_data, calibration, outside_std_range_flag = TRUE)

Arguments

stic_data	A data frame with a column named condUncal, for example as produced by the function tidy_hobo_data.
calibration	a model object relating condUncal to a standard of some sort, for example as produced by the function get_calibration.
outside_std_range_flag	a logical argument indicating whether the user would like to include an additional column flagging (with the letter "O") instances where the calibrated SpC value is outside the range of standards used to calibrate it.

Value

The same data frame as input, except with a new column called SpC. This will be in the same units as the data used to develop the model calibration.

Examples

calibration <- get_calibration(calibration_standard_data)
calibrated_df <- apply_calibration(tidy_stic_data, calibration, outside_std_range_flag = TRUE)
head(calibrated_df)

---

Example calibrated STIC output data.

Description

Calibrated STIC data used for function examples.

Usage

calibrated_stic_data

Format

## 'calibrated_stic_data' A data frame with 1000 rows and 4 columns:

datetime

Date and time of measurement.

condUncal

Raw uncalibrated conductivity recorded by STIC logger.

tempC

Temperature recorded by STIC logger.

SpC

Specific conductance calculated using 'apply_calibration' function.

Source

AIMS project data.

---

Example calibration STIC lab data.

Description

Example calibration data for STIC sensor for conversion from uncalibrated conductivity to specific conductivity ('SpC').

Usage

calibration_standard_data

Format

## 'calibration_standard_data' A data frame with 4 rows and 3 columns:

sensor

Serial number for STIC sensor.

standard

Specific conductance ('SpC') standard values used for soaking STIC.

condUncal

Uncalibrated conductivity recorded by STIC when soaked in each standard.

Source

AIMS project data.

---

Example classified STIC output data.

Description

Classified STIC data used for function examples.

Usage

classified_df

Format

## 'classified_df' A data frame with 1000 rows and 5 columns:

datetime

Date and time of measurement.

condUncal

Raw uncalibrated conductivity recorded by STIC logger.

tempC

Temperature recorded by STIC logger.

SpC

Specific conductance calculated using 'apply_calibration' function.

wetdry

Classified STIC data created by 'classify_wetdry' function.

Source

AIMS project data.

---

classify_wetdry

Description

This is a function to classify STIC data into a binary "wet" and "dry" column. Data can be classified according to any classification variable defined by the user. User can choose one of two methods for classification: either an absolute numerical threshold or as a chosen percentage of the maximum value of the classification variable.

Usage

classify_wetdry(stic_data, classify_var, threshold, method)

Arguments

stic_data	A data frame with STIC data, such as that produced by apply_calibration or tidy_hobo_data.
classify_var	Name of the column in data frame you want to use for classification.
threshold	This is the user-defined threshold for determining wet versus dry based on the designated classification variable. If using the "absolute" method, the threshold will be a value in the same units as the designated classification variable. If using the "percent" method, the value will be a decimal percentage (range 0-1) of the max value of the classification variable in the data frame. Values above this proportion of the maximum will be designated as wet. If using the "y-intercept" method, this should be a model fit used to generate calibrated SpC values such as that produced by get_calibration.
method	User chooses which classification method used to generate the binary data. "absolute" uses an absolute numerical threshold for classifying wet vs dry. "percent" uses a threshold based on a given percentage of the maximum value of the classification variable in the data frame. "y-intercept" uses the y-intercept from the get_calibration function.

Value

The same data frame as input, but with a new column called "wetdry".

Examples

classified_df <-
  classify_wetdry(calibrated_stic_data,
    classify_var = "SpC", method = "absolute", threshold = 200
  )
head(classified_df)

---

Example field observations that could be compared to classified STIC data.

Description

Example field observations that could be compared to classified STIC data.

Usage

field_obs

Format

## 'field_obs' A data frame with 5 rows and 3 columns:

datetime

Date and time of field observation.

wetdry

Field observation of stream water status ('wet' or 'dry').

SpC

Field observations of specific conductance.

Source

Made up data.

---

get_calibration

Description

This is a function to fit specific conductivity (SpC) standards and uncalibrated conductivity measured by the STIC to a model object. This model can then be used to predict SpC values using apply_calibration. As of right now, only linear models are supported.

Usage

get_calibration(calibration_data)

Arguments

calibration_data

STIC calibration data frame with columns "standard" and "condUncal".

Value

A fitted lm model object relating SpC to the uncalibrated conductivity values measured by the STIC

Examples

head(calibration_standard_data)
lm_calibration <- get_calibration(calibration_standard_data)
summary(lm_calibration)

---

qaqc_stic_data

Description

This function provides multiple options for QAQC flagging of processed and classified STIC data frames, such as those generated by the classify_wetdry function. Users can select which operations are to be performed, and a single new QAQC column is created with all flags concatenated. QAQC options currently include: (1) correction and flagging of negative SPC values resulting from the calibration process, i.e., changing the negative values to 0 and flagging this (2) inspecting the wetdry classification time series for potential deviation anomalies based on user-defined windows

Usage

qaqc_stic_data(
  stic_data,
  spc_neg_correction = TRUE,
  inspect_deviation = TRUE,
  deviation_size = NULL,
  window_size = NULL
)

Arguments

stic_data	A data frame with classified STIC data, such as that produced by classify_wetdry.
spc_neg_correction	a logical argument indicating whether the user would like to correct negative SPC values resulting from the calibration process to 0. The character code associated with this correction is "C".
inspect_deviation	a logical argument indicating whether the user would like to identify deviation anomalies, in which a series of wet or dry readings less than or equal to 'deviation_size' in length is surrounded on both sides by 'window_size' or more observations of its opposite. This operation is meant to identify potentially suspect binary wet/dry data points for further examination. The character code associated with this operation is "D".
deviation_size	a numeric argument specifying the maximum size (i.e., number of observations) of a clustered group of points that can be flagged as an deviation
window_size	a numeric argument specifying the minimum size (i.e., number of observations) that the deviation must be surrounded by in order to be flagged

Value

The same data frame as input, but with new QAQC columns or a single, concatenated QAQC column. The QAQC output Can include: "C", meaning the calibrated SpC value was negative from 'spc_neg_correction'; "D", meaning the point was identified as a deviation or deviation based on a moving window from 'inspect_deviation'; or "O", meaning the calibrated SpC was outside the standard range based on the function apply_calibration.

Examples

qaqc_df <-
  qaqc_stic_data(classified_df,
    spc_neg_correction = TRUE,
    inspect_deviation = TRUE,
    deviation_size = 4, window_size = 96
  )
head(qaqc_df)

---

test_threshold.R

Description

This function is intended to allow the user to visually assess the effects of classification threshold uncertainty on STIC classification. It takes the the model object used to calibrate SpC, as well as a classified STIC data frame with column names matching those produced by classify_wetdry.

Usage

test_threshold(stic_data, calibration)

Arguments

stic_data	classified STIC data frame with the variable names of that produced by classify_wetdry
calibration	the model object used to calibrate SpC, generated by the get_calibration function and used in apply_calibration

Value

A time series plot of classified wet/dry observations through time using three different absolute classification thresholds: the y-intercept of the fitted model developed in get_calibration, the y-intercept plus one standard error, and the y-intercept minus one standard error

Examples

lm_calibration <- get_calibration(calibration_standard_data)
threshold_testing_plot <- test_threshold(stic_data = classified_df, calibration = lm_calibration)

---

tidy_hobo_data

Description

This function loads raw HOBO STIC CSV files and cleans up columns and headers

Usage

tidy_hobo_data(infile, outfile = FALSE, convert_utc = TRUE)

Arguments

infile	filename (including path or URL if needed) for a raw CSV file exported from HOBOware.
outfile	filename (including path if needed) to save the tidied data frame. Defaults to FALSE, in which case tidied data will not be saved.
convert_utc	a logical argument indicating whether the user would like to convert from the time zone associated with their CSV to UTC

Value

a tidied data frame with the following column names: datetime, condUncal, tempC.

Examples

clean_data <-
  tidy_hobo_data(
    infile = "https://samzipper.com/data/raw_hobo_data.csv",
    outfile = FALSE, convert_utc = TRUE
  )
head(clean_data)

---

Example tidied STIC output data.

Description

Example tidied STIC data for input to calibration and classification process.

Usage

tidy_stic_data

Format

## 'tidy_stic_data' A data frame with 1000 rows and 3 columns:

datetime

Date and time of measurement.

condUncal

Raw uncalibrated conductivity recorded by STIC logger.

tempC

Temperature recorded by STIC logger.

Source

AIMS project data.

---

trim_hobo_data

Description

This function trims a tidied hobo data frame by datetime to eliminate periods where the logger wad recording but not placed in the stream network

Usage

trim_hobo_data(
  stic_data,
  time_start = "2021-07-16 18:00:00",
  time_end = "2021-07-27 01:00:00"
)

Arguments

stic_data	A data frame with columns named condUncal and datetime, for example as produced by the function tidy_hobo_data.
time_start	User enters the time at which the logger was placed in the stream network
time_end	User enters the time at which the logger was removed from the stream network

Value

a tidied data frame with the same columns as the input, but trimmed to the user-defined time

Examples

trimmed_data <-
  trim_hobo_data(tidy_stic_data,
    time_start = "2021-07-16 18:00:00",
    time_end = "2021-07-27 01:00:00"
  )
head(trimmed_data)

---

validate_stic_data.R

Description

This function takes a data frame with field observations of wet/dry status and SpC and generates both a confusion matrix for the wet/dry observations and a scatterplot comparing estimated SpC from the STICs to field-measured values.

Usage

validate_stic_data(
  stic_data,
  field_observations,
  max_time_diff,
  join_cols,
  get_SpC
)

Arguments

stic_data	classified STIC data frame with the variable names of that produced by classify_wetdry. At a minimum, there must be datetime, condUncal, and wetdry columns, and an SpC column if get_SpC = T.
field_observations	The input data frame of field observations must include a datetime column (in POSIXct format), as well as a column labeled wetdry consisting of the character strings “wet” or “dry” (as in the processed STIC data itself). Additionally, if field data on SpC was collected (e.g., with a sonde), this should be included as a third column called SpC, and units should be in µS/cm.
max_time_diff	Maximum allowed time difference (in minutes) between field observation and STIC reading to be counted as a match.
join_cols	A named vector of columns that need to be matched between stic_data and field_observations in addition to datetime. This could include, for instance, a column specifying the site at which the observation was collected. Should be in the format of c("col_name_in_stic_data" = "col_name_in_field_observations") and can have as many columns as desired. If there are no additional columns to be matched, set to NULL.
get_SpC	Logical flag whether to get STIC data for SpC (T) or not (T). You must have an SpC column in both stic_data and field_observations if this is used.

Value

The field_observations data frame with new columns indicating the closest-in-time STIC wetdry classification (wetdry_STIC), SpC measurement (SpC_STIC; only if get_SpC = T), and time difference between the field observation and STIC reading (timediff_min).

Examples

stic_validation <-
  validate_stic_data(
    stic_data = classified_df,
    field_observations = field_obs,
    max_time_diff = 30,
    join_cols = NULL,
    get_SpC = TRUE
  )

---