fpl {richards} | R Documentation |
The four parameter logistic function, the inverse of the
function, and the derivative of fpl(x)
and fpl(exp(x))
.
fpl(x, a = 0.1, d = 2.4, e = 100, b = 1) fpl.deriv(x, a = 0.1, d = 2.4, e = 100, b = 1) fpl.deriv.x(x, a = 0.1, d = 2.4, e = 100, b = 1) fpl.inv(y, a = 0.1, d = 2.4, e = 100, b = 1)
x |
a numeric vector of values at which to evaluate the function. |
y |
a numeric vector of values at which to evaluate the inverse function. |
a |
a numeric parameter representing the horizontal asymptote on the
left side (very small values of input) for b positive,
else the horizontal asymptote on the right side. |
d |
a numeric parameter representing the horizontal asymptote on the
right side (very large values of input) for b positive,
else the horizontal asymptote on the left side. |
b |
a numeric scale parameter on the input axis, 'growth rate'. |
e |
the parameter representing the input value at the
inflection point of the curve. The value of fpl
will be midway between a and d at e . |
A vector with function values.
Jens Henrik Badsberg