make_guess_primary {biogrowth}  R Documentation 
The function uses some heuristics to provide initial guesses for the parameters
of the growth model selected that can be used with fit_growth()
.
make_guess_primary(
fit_data,
primary_model,
logbase_mu = 10,
formula = logN ~ time
)
fit_data 
the experimental data. A tibble (or data.frame) with a column
named 
primary_model 
a string defining the equation of the primary model,
as defined in 
logbase_mu 
Base of the logarithm the growth rate is referred to. By default, 10 (i.e. log10). See vignette about units for details. 
formula 
an object of class "formula" describing the x and y variables.

A named numeric vector of initial guesses for the model parameters
## An example of experimental data
my_data < data.frame(time = 0:9,
logN = c(2, 2.1, 1.8, 2.5, 3.1, 3.4, 4, 4.5, 4.8, 4.7))
## We just need to pass the data and the model equation
make_guess_primary(my_data, "Logistic")
## We can use this together with fit_growth()
fit_growth(my_data,
list(primary = "Logistic"),
make_guess_primary(my_data, "Logistic"),
c()
)
## The parameters returned by the function are adapted to the model
make_guess_primary(my_data, "Baranyi")
## It can express mu in other logbases
make_guess_primary(my_data, "Baranyi", logbase_mu = exp(1)) # natural
make_guess_primary(my_data, "Baranyi", logbase_mu = 2) # base2