Interactive drift correction editor — editASRdrift • AquaSensR

Opens a Shiny application for interactively correcting instrument drift in continuous water quality monitoring data. Click the plot twice to mark the start and end of a drift period, enter the reference value measured by an independent calibrated instrument at the end of the deployment, and click Apply Correction. A third click resets the selection. Clicking Done / Close stops the app. Choose Close, save corrections to return the corrected data or Close, discard corrections to return the original unmodified data.

Usage

editASRdrift(cont, ext = NULL)

Arguments

cont: contdat data frame returned by readASRcont
ext: Optional external data frame returned by readASRcont, with a DateTime column plus one or more parameter columns from a second file (e.g. a separate logger not otherwise included in cont). When supplied, each column is added as an additional entry in the Overlay drop-down (see Controls below) so it can be plotted alongside any parameter. Its DateTime column is aligned to cont's time zone and clipped to cont's date range. Entries are omitted entirely if the two do not overlap.

Value

A list with two elements, invisibly returned after the app closes:

contdat: A data frame with the same structure as the input cont (sorted by DateTime), with drift-corrected values replacing the originals in all corrected windows.
corrections: A data frame summarising every correction applied, with columns Parameter, drift_start, drift_end, cal_ref, cal_check, and drift_applied.

Details

How to correct drift

Zoom and pan with the plot toolbar to identify the drift period. Click once to set the start time and click again to set the end time. Clicking a third time resets the selection. Once two times are selected, enter the Reference value (the true reading from an independent calibrated instrument at the end of the deployment) and click Apply Correction.

The cal_check value (the deployed sensor reading at the end of the window) is inferred automatically from the data. The correction is distributed linearly across the window: zero at the start, full correction at the end. See utilASRdrift for the algorithm.

After a correction is applied, the plot retains the original (pre-correction) values for the window as a solid gray line so the adjustment can be assessed visually. A red circle marks the supplied reference value at the end of the window. These elements are display-only and are not included in the returned data.

Multiple corrections can be applied per parameter (e.g., one per deployment period), and each can be individually undone.

Controls

Parameter: drop-down selector to switch between parameters. Corrections are tracked independently for each parameter.
Overlay: optional drop-down to display a second parameter from contdat on a right-side y-axis, useful for spotting co-occurring changes across parameters. If an ext argument was supplied, one additional entry per column in that file is also available, labeled with an "[External File]" suffix.
USGS Overlay: enter a USGS site number and select a parameter type, then click Load to fetch continuous data from NWIS and display it on the secondary y-axis. Loading USGS data clears any Overlay selection and selecting an Overlay entry clears the USGS data. Site numbers can be found at the NWIS Mapper (https://apps.usgs.gov/nwismapper).
Undo Last Correction: reverses the most recently applied correction for the current parameter.
Start Over: restores all original values for every parameter and clears the corrections log.
Export Progress: saves the current corrected data and corrections log as Excel files in a ZIP archive.
Done / Close: stops the app. Choosing Close, save corrections returns the corrected data and corrections summary. Choosing Close, discard corrections returns the original unmodified data. Closing the browser tab or window directly (without clicking Done / Close) also saves corrections, equivalent to Close, save corrections. Refreshing the page has the same effect and ends the session, since a refresh disconnects the browser from the running app. If any corrections have been applied in the current session, closing or refreshing this way triggers the browser's own "leave site?" confirmation as a warning. Dismissing that warning by declining it keeps the session open. This warning does not appear when closing via Done / Close, since that choice is already explicit.

Examples

if (FALSE) { # \dontrun{
contpth <- system.file("extdata/ExampleCont1.xlsx", package = "AquaSensR")
contdat <- readASRcont(contpth)
result  <- editASRdrift(contdat)

# Optional external overlay from a second file
extpth <- system.file("extdata/ExampleFlow1.xlsx", package = "AquaSensR")
extdat <- readASRcont(extpth)
result2 <- editASRdrift(contdat, ext = extdat)
} # }