SSmicmen
Michaelis-Menten Model

### Description

Fits a Michaelis-Menten model to the data. This is a selfStart function.

### Usage

    SSmicmen(input, Vm, K)

### Arguments

input | a numeric vector of values at which to evaluate the model. Usually, this represents the concentration of a reactant, and the response represents the velocity of the reaction at those substrate concentrations.
Vm | a numeric parameter representing the maximum value of the response.
K | a numeric parameter representing the input value at which half the maximum response is attained. In the field of enzyme kinetics, this parameter is called the Michaelis parameter.

### Details

Because this is a selfStart function, it has an attribute called "initial", which is a function that nls can call to compute reasonable starting values for fitting a Michaelis-Menten model to data.
Value
returns a numeric vector of the same length as input. It is the value of the expression Vm*input/(K+input). If both of the arguments Vm and K are names of objects, the gradient matrix with respect to these names is attached as an attribute named gradient.
Note
This is primarily intended for use in formulae given to nls function or similar functions.
See Also
nls, selfStart.
Examples

    SSmicmen(1:6, Vm=17, K=5)
    with(list(Vmax=17, KM=5), SSmicmen(1:6, Vmax, KM))
    tDat <- data.frame(
        conc = c(0.5, 1, 2, 3, 4),
        rate = c(0.2, 2.0, 2.5, 2.8, 3.0))
    nls(rate ~ SSmicmen(conc, Vmax, KM), data=tDat)

Package stats version 6.1.5-18
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