LCxt {morseTKTD}R Documentation

Predict Lethal Concentration at any specified time point.

Description

Predict the Lethal Concentration at any specified time point for a SurvFit object.

The function LCx, x\ the dose required to kill x\ after a specified test duration (time_LCx) (default is the maximum time point of the experiment).

Mathematical definition of x\ denoted LC(x,t), is:

S(LC(x,t), t) = S(0, t)*(1- x/100),

where S(LC(x,t), t) is the survival probability at concentration LC(x,t) at time t, and S(0,t) is the survival probability at no concentration (i.e. concentration is 0) at time t which reflect the background mortality h_b:

S(0, t) = exp(-hb* t).

In the function LCx, we use the median of S(0,t) to rescale the x\

Usage

lcxt(fit, x, t, ...)

## S3 method for class 'SurvFit'
lcxt(
  fit,
  x = 0.5,
  t = NULL,
  exposure_range = NULL,
  interpolate_length = 50,
  ...
)

Arguments

fit

An object used to select a method

x

rate of individuals dying (e.g., 0.5 for LC_{50}, 0.1 for LC_{10}, ...).

t

A number giving the time at which LC_{x} has to be estimated. If NULL, the latest time point of the experiment is used.

...

Further arguments to be passed to generic methods

exposure_range

A vector of length 2 with minimal and maximal value of the range of concentration. If NULL, the range is define between 0 and the highest tested concentration of the experiment.

interpolate_length

of time point in the range of concentration between 0 and the maximal concentration. 100 by default. description.

Value

The function returns an object of class LCx, which is a list with the following information:


[Package morseTKTD version 0.1.3 Index]