Apply rate-of-change QC flag

Apply rate-of-change QC flag

Usage

utilASRflagroc(flag, vals, datetimes, dqo)

Arguments

flag

character vector of current flag values ("pass", "suspect", or "fail").

vals

numeric vector of observed values, the same length as flag.

datetimes

POSIXct vector of observation timestamps, the same length as flag.

dqo

two-row data frame from data quality objectives for the parameter being checked, containing one row where Flag == "Fail" and one where Flag == "Suspect". Each row's numeric columns RoCStDv (SD multiplier) and RoCHours (trailing window width in hours) control the check independently. If either column is NA for a given row that severity level is skipped entirely.

Value

Updated character flag vector.

Details

For each observation the standard deviation of all raw values within a trailing RoCHours-hour window ending just before (and excluding) that observation is multiplied by RoCStDv to produce a threshold. The observation is flagged if the absolute lag-1 difference exceeds that threshold — "suspect" using the "Suspect" row thresholds and "fail" using the "Fail" row thresholds. At least 2 values must fall within the window to compute the standard deviation; otherwise the observation is skipped. Flags are only ever upgraded (pass -> suspect -> fail), never downgraded.

Examples

flag <- rep("pass", 6)
vals <- c(10, 10.2, 10.1, 10.3, 15.0, 10.2)
datetimes <- as.POSIXct("2024-01-01") + seq(0, 5) * 900  # 15-min intervals
dqo <- data.frame(Flag = c("Fail", "Suspect"), RoCStDv = c(2, 3), RoCHours = c(2, 2))
utilASRflagroc(flag, vals, datetimes, dqo)
#> [1] "pass" "pass" "pass" "pass" "pass" "pass"