ProbitWeightingCoef {ecotoxicology} | R Documentation |
Returns the weighting coefficient
ProbitWeightingCoef(Z, Q, P, C)
Z |
numeric, ordinate to the normal distribution corresponding to the probability P |
Q |
numeric, 1-P |
P |
numeric, Probability P of expected probit |
C |
numeric, proportion of natural mortality |
the weighting coefficient
Jose Gama
Finney D. J., 1964 Probit analysis: a statistical treatment of the sigmoid response curve. Cambridge University Press. Formula 6.3.
# Example from page 90 of Finney 1964: # expected probit Y = 6.2, control mortality C = 59% Y <- 6.2 C <- 0.59 P <- pnorm(Y-5) Q <- 1-P Z <- ProbitZ(Y) # weighting coefficient = 0.141 ProbitWeightingCoef(Z,Q,P,C)