Calculate the total pressure in bar

Calculates the total pressure in bar. Licor gas exchange measurement systems report both the abient air pressure (Pa) and the chamber overpressure (DeltaPcham) in kPa; the total pressure in the chamber is therefore given by the sum of these two columns. This function can accomodate alternative column names for the variables taken from Licor log files in case they change at some point in the future. This function also checks the units of each required column and will produce an error if any units are incorrect.

Usage

calculate_total_pressure(
    exdf_obj,
    pa_column_name = 'Pa',
    deltapcham_column_name = 'DeltaPcham'
  )

Arguments

exdf_obj

An exdf object that contains pressure measurements.

pa_column_name

The name of the column in exdf_obj that contains the ambient air pressure in kPa.

deltapcham_column_name

The name of the column in exdf_obj that contains the chamber overpressure in kPa.

Details

If deltapcham_column_name is NA, this function will simply convert the values in the pa_column_name to units of bar. Otherwise, the values from the pa_column_name and deltapcham_column_name columns will be added together and converted to bar.

Value

An exdf object based on exdf_obj that includes the total pressure values in a new column called total_pressure. The category of this new column is calculate_total_pressure to indicate that it was created using this function.

Examples

# Read an example Licor file included in the PhotoGEA package and calculate the
# total pressure.
licor_file <- read_gasex_file(
  PhotoGEA_example_file_path('ball_berry_1.xlsx')
)

licor_file <- calculate_total_pressure(licor_file)

licor_file$units$total_pressure      # View the units of the new `total_pressure` column
#> [1] "bar"
licor_file$categories$total_pressure # View the category of the new `total_pressure` column
#> [1] "calculate_total_pressure"
licor_file[, 'total_pressure']       # View the values of the new `total_pressure` column
#>  [1] 0.9925101 0.9925749 0.9926076 0.9926272 0.9924095 0.9924228 0.9924457
#>  [8] 0.9925986 0.9926574 0.9928725 0.9929653 0.9929991 0.9928978 0.9929064
#> [15] 0.9929203 0.9929226 0.9929827 0.9929333 0.9929934 0.9926874 0.9926688
#> [22] 0.9923497 0.9924241 0.9923444 0.9923882 0.9923838 0.9923927 0.9921658