Two-point drift correction

Source: R/dr_correctTwo.R

A wrapper around dplyr::mutate() that creates a corrected value for each observation of the specified variable based on two data points.

dr_correctTwo(.data, sourceVar, cleanVar, calValLow, calStdLow,
                      calValHigh, calStdHigh, factorVar)

Arguments

.data

A tbl
sourceVar

Name of variable to correct
cleanVar

New variable name for corrected data
calValLow

A numeric value; the number that the instrument was actually reading for the low standard
calStdLow

A numeric value; the number that the instrument should have been reading for that standard; i.e. the low standard value
calValHigh

A numeric value; the number that the instrument was actually reading for the high standard
calStdHigh

A numeric value; the number that the instrument should have been reading for that standard; i.e. the high standard value
factorVar

Name of variable generated using dr_factor

Value

An object of the same class as .data with the new corrected variable added to the other data in .data.

Details

This command takes the raw data from the water-quality instrument, utilizes the values generated from dr_factor and returns data that accounts for drift over time. This is done via a two-point calibration standard, which it typical for pH and chloride.

See also

dr_factor for correction factor creation, dr_correctOne for the two-point drift correction

Examples

testData <- data.frame(
   Date = c("9/18/2015", "9/18/2015", "9/18/2015", "9/18/2015", "9/18/2015", "9/18/2015"),
   Time = c("12:10:49", "12:15:50", "12:20:51", "12:25:51", "12:30:51", "12:35:51"),
   Temp = c(14.76, 14.64, 14.57, 14.51, 14.50, 14.63),
   pH = c(7.18, 7.14, 7.14, 7.13, 7.13, 7.13),
   corrFac = c(0.0000000, 0.2003995, 0.4007989, 0.6005326, 0.8002663, 1.0000000),
   stringsAsFactors = FALSE
 )

 dr_correctTwo(testData, sourceVar = pH, cleanVar = pH_Corr, calValLow = 7.01, calStdLow = 7,
     calValHigh = 11.8, calStdHigh =  10, factorVar = corrFac)
#>        Date     Time  Temp   pH   corrFac  pH_Corr
#> 1 9/18/2015 12:10:49 14.76 7.18 0.0000000 7.180000
#> 2 9/18/2015 12:15:50 14.64 7.14 0.2003995 7.126687
#> 3 9/18/2015 12:20:51 14.57 7.14 0.4007989 7.115966
#> 4 9/18/2015 12:25:51 14.51 7.13 0.6005326 7.099834
#> 5 9/18/2015 12:30:51 14.50 7.13 0.8002663 7.093067
#> 6 9/18/2015 12:35:51 14.63 7.13 1.0000000 7.087318