This
selfStart model evaluates the asymptotic regression
function through the origin and its gradient. It has an
initial
attribute that will evaluate initial estimates of the
parameters
Asym and
lrc for a given set of data.
USAGE:
SSasympOrig(input, Asym, lrc)
REQUIRED ARGUMENTS:
input
a numeric vector of values at which to evaluate the model.
Asym
a numeric parameter representing the horizontal asymptote.
lrc
a numeric parameter representing the natural logarithm of
the rate constant.
VALUE:
a numeric vector of the same length as
input. It is the value of
the expression
Asym*(1 - exp(-exp(lrc)*input)). If all of the
arguments
Asym and
lrc are names of objects, the gradient matrix
with respect to these names is attached as an attribute named
gradient
.