create_equations {gasanalyzer}

Create a list of equations for recalculating gasanalyzer data.

Description

This function creates a list of equations that can be used to recalculate gas-exchange data by passing the resulting object to the recalculate() method. Various useflags can be defined to tune the equations. In addition, custom equations can be defined as arguments. Note that the calculations may fail if commons are missing in the gas-exchange data.

Usage

create_equations(useflags = "default", ...)

Arguments

useflags

character vector with the type of equations to create (such as c("li6800", "gfs3000")). Leave empty to obtain the default set. An unknown flag returns an empty list, and a warning listing all valid flags.

...

custom equations. the arguments must tagged function expressions. Note that the function body must be wrapped in curly brackets. The tags will be matched against the names of a data frame when applying the return value with recalculate().

Value

A list of language objects with equations

See Also

read_6800_equations()

Examples

exampledir <- system.file("extdata", package = "gasanalyzer")

# import factory calibration for example data:
import_factory_cals(exampledir)

# read data from a txt file:
li6800 <- read_6800_txt(file.path(exampledir, "lowo2"))

# passing an invalid flags shows which flags are valid:
create_equations("help")

# create a default set of gas-exchange equations, for the 6800, but overwrite
# the default calculation of leaf light absorption with a custom value:
Eqs <- create_equations(c("default", "li6800"), LeafQ.alpha = \() {0.86})

#apply:
li6800_recalc <- recalculate(li6800, Eqs)

li6800$LeafQ.alpha
li6800_recalc$LeafQ.alpha