This
selfStart model evaluates the Michaelis-Menten model and
its gradient. It has an
initial attribute that
will evaluate initial estimates of the parameters
Vm and
K
USAGE:
SSmicmen(input, Vm, K)
REQUIRED ARGUMENTS:
input
a numeric vector of values at which to evaluate the model.
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 is called the Michaelis parameter.
VALUE:
a numeric vector of the same length as
input. It is the value of
the expression
Vm*input/(K+input). If both
the arguments
Vm and
K are
names of objects, the gradient matrix with respect to these names is
attached as an attribute named
gradient.
SEE ALSO:
,
EXAMPLES:
PurTrt <- Puromycin[ Puromycin$state == "treated", ]
SSmicmen( PurTrt$conc, 200, 0.05 ) # response only
Vm <- 200
K <- 0.05
SSmicmen( PurTrt$conc, Vm, K ) # response and gradient