Calculates lethal time (LT) and its fiducial confidence limits (CL) using a probit analysis according to Finney 1971, Wheeler et al. 2006, and Robertson et al. 2007. LT() is deprecated use LT_probit() for probit analysis.
LT(formula, data, p = seq(1, 99, 1), weights = NULL, het_sig = NULL, conf_level = NULL)an object of class formula or one that can be coerced to that class: a symbolic description of the model to be fitted.
an optional data frame, list or environment (or object coercible by as.data.frame to a data frame) containing the variables in the model. If not found in data, the variables are taken from environment(formula), typically the environment from which LT is called.
Lethal time (LT) values for given p, example will return a LT50 value if p equals 50. If more than one LT value desired specify by creating a vector.
vector of 'prior weights' to be used in the fitting process. Should be a numeric vector, if set to NULL weights will not be used.
signficance level from person's goodness-of-fit test that is used to decide if a hetrogentiy factor is used. NULL is set to 0.15.
Adjust confidence level as necessary or NULL set at 0.95.
Returns a data frame with predicted LT for given p level, lower CL (LCL), upper CL (UCL), LCL and UCL distance away from LT (LCL_dis & UCL_dis; important for creating a plot), Pearson's goodness-of-fit test, slope, intercept, slope and intercept p values and standard error, and LT variance.
Finney, D.J., 1971. Probit Analysis, Cambridge University Press, Cambridge, England, ISBN: 052108041X
Wheeler, M.W., Park, R.M., and Bailey, A.J., 2006. Comparing median lethal concentration values using confidence interval overlap or ratio tests, Environ. Toxic. Chem. 25(5), 1441-1444.10.1897/05-320R.1
Robertson, J.L., Savin, N.E., Russell, R.M. and Preisler, H.K., 2007. Bioassays with arthropods. CRC press. ISBN: 9780849323317
# NOT RUN {
#This function is deprecated use LT_probit() to calculate lethal times.
# }
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