effective_dose {drda} | R Documentation |
Estimate effective doses, that is the x
values for which f(x) = y
.
effective_dose(object, y, type, level)
object |
fit object as returned by |
y |
numeric vector with response levels (default 0.5). |
type |
character string with either "relative" (default) or "absolute". |
level |
level of confidence intervals (default 0.95). |
Given a fitted model f(x; theta)
we seek the values x
at which the
function is equal to the specified response values.
If responses are given on a relative scale (type = "relative"
), then y
is
expected to range in the interval (0, 1)
.
If responses are given on an absolute scale (type = "absolute"
), then y
is free to vary on the whole real line. Note, however, that the solution
does not exist when y
is not in the image of the function.
Numeric matrix with the effective doses and the corresponding
confidence intervals. Each row is associated with each value of y
.
drda_fit <- drda(response ~ log_dose, data = voropm2)
effective_dose(drda_fit)
# relative values are given on the (0, 1) range
effective_dose(drda_fit, y = c(0.2, 0.8))
# explicitly say when we are using actual response values
effective_dose(drda_fit, y = c(0.2, 0.8), type = "absolute")
# use a different confidence level
effective_dose(drda_fit, y = 0.6, level = 0.8)