step1_down_basic {AccelStab} | R Documentation |
Basic version Step1 Down Model
Description
Quickly fit the one-step Šesták–Berggren kinetic model.
Usage
step1_down_basic(
data,
y,
.time,
K = NULL,
C = NULL,
validation = NULL,
parms = NULL,
reparameterisation = FALSE,
zero_order = FALSE
)
Arguments
data |
Dataframe containing accelerated stability data (required). |
y |
Name of decreasing variable (e.g. concentration) contained within data (required). |
.time |
Time variable contained within data (required). |
K |
Kelvin variable (numeric or column name) (optional). |
C |
Celsius variable (numeric or column name) (optional). |
validation |
Validation dummy variable, the column must contain only 1s and 0s, 1 for validation data and 0 for fit data. (column name) (optional). |
parms |
Starting values for the parameters as a list - k1, k2, k3, and c0. |
reparameterisation |
Use alternative parameterisation of the one-step model which aims to reduce correlation between k1 and k2. |
zero_order |
Set kinetic order, k3, to zero (straight lines). |
Details
Fit the one-step Šesták–Berggren kinetic (non-linear) model using accelerated stability data from an R dataframe format. Fit summary is printed to the console and the fit itself is returned. Fewer arguments and outputs than the main function for rapid testing. Parameters are kept in even when not significant.
Value
The fit object
Examples
#load antigenicity and potency data.
data(antigenicity)
data(potency)
#Use of the step1_down_basic function with C column defined.
fit1 <- step1_down_basic(data = antigenicity, y = "conc", .time = "time", C = "Celsius")
#Basic use of the step1_down_basic function with K column defined & Validation data segmented out.
fit2 <- step1_down_basic(data = antigenicity, y = "conc", .time = "time", K = "K",
validation = "validA")
#When zero_order = FALSE, the output suggests using zero_order = TRUE for Potency dataset.
fit3 <- step1_down_basic(data = potency, y = "Potency", .time = "Time",C = "Celsius",
reparameterisation = FALSE, zero_order = TRUE)
#reparameterisation is TRUE.
fit4 <- step1_down_basic(data = antigenicity, y = "conc", .time = "time",C = "Celsius",
reparameterisation = TRUE)