convert_DO function

Convert between units of dissolved oxygen

This is a conversion function that performs conversions between concentration and pressure units of dissolved oxygen (DO).

convert_DO(
  x,
  from = NULL,
  to = NULL,
  S = NULL,
  t = NULL,
  P = NULL,
  simplify = TRUE
)

Arguments

• x: numeric. The dissolved oxygen (DO) value(s) to be converted.
• from: string. The DO unit to convert from. See unit_args() for details.
• to: string. The DO unit to convert to. See unit_args() for details.
• S: numeric. Salinity (ppt). Defaults to NULL. Required for conversion of some units. See unit_args() for details.
• t: numeric. Temperature(°C). Defaults to NULL. Required for conversion of some units. See unit_args() for details.
• P: numeric. Pressure (bar). Defaults to 1.013253. Required for conversion of some units. See unit_args() for details.
• simplify: logical. Defaults to TRUE in which case the converted values are returned as a numeric vector. if FALSE a list object of class convert_DO is returned.

Returns

By default (simplify = TRUE) the output is a numeric vector of converted values. If simplify = FALSE output is a list object of class convert_DO containing five elements: $call the function call, $input

values, $output converted values, $input.unit and $output.unit.

More

For additional help, documentation, vignettes, and more visit the respR

website at https://januarharianto.github.io/respR/

Details

The function uses a fuzzy string matching algorithm to accept various unit formatting styles. For example, "mg/l", "mg/L", "mgL-1", "mg l-1", "mg.l-1" are all parsed the same. See [unit_args()] for details of accepted units.

Oxygen concentration units should use SI units (L or kg) for the denominator.

Some DO units require temperature (t), salinity (S), and atmospheric pressure (P) to be specified; if this is the case the function will stop and prompt for them. For the atmospheric pressure input (P), a default value of 1.013 bar (standard pressure at sea level) is applied if not otherwise entered. For freshwater experiments, salinity should be set to zero (i.e. S = 0).

S3 Generic Functions

Saved output objects (if simplify = FALSE is used) can be entered in the generic S3 functions print() and summary().

• print(): prints input and converted values (up to first 20), plus input and output units.
• summary(): simple wrapper for print() function. See above.

Examples

# Convert a numeric value to units which do not require t, S and P
convert_DO(8.21, from = "mg/L", to = "umol/L")

# Convert a numeric value to units which require t, S and P
convert_DO(100, from = "%Air", to = "mg L-1", S = 33, t = 18)
convert_DO(214, from = "hPa", to = "mL/kg", S = 33, t = 18)

# Convert a vector of values
convert_DO(urchins.rd[[5]], from = "mg/L", to = "umol/L")
convert_DO(c(8.01, 8.03, 8.05), from = "mg per litre", to = "%Air",
  t = 15, S = 35)
convert_DO(sardine.rd[[2]], from = "%Air", to = "torr",
  t = 15, S = 35)