ECx {mixtox} | R Documentation |
Effect Concentration Calculation for Sigmoidal Models
Description
Effect concentrations are calculated at particular effects based on the fitting coefficients of 13 sigmoidal models.
Usage
ECx(model, param, effv, rtype = 'quantal', Scaled = TRUE, sav = FALSE)
Arguments
model |
a character vector of equations:("Hill", "Hill_two", "Hill_three", "Hill_four", "Weibull", "Weibull_three", "Weibull_four", "Logit", "Logit_three", "Logit_four", "BCW(Box-Cox-Weibull)", "BCL(Box-Cox-Logit)", "GL(Generalized Logit)") |
param |
a numeric matrix of fitting coefficients with rownames (equations) and colnames (Alpha, Beta, Gamma, Delta, and Epsilon). |
effv |
a numeric vector with single or multiple effect values |
rtype |
the response type of endpoint: 'continuous' or 'quantal' data. |
Scaled |
only for 'continuous' data. To indicate if the effv is scaled by response ranges to 0~1 or not (default is TRUE). |
sav |
TRUE: save output to a default file; FALSE: output will not be saved; a custom file directory: save output to the custom file directory. |
Details
effect concentrations will be calculated with provided equations (model), associated
fitting parameters (param), and effect levels (effv). For example,
should be 0.5 if we want to calculate a concentration
causes 50% effect.
The inverse functions of the six quantal sigmoidal equations are listed as follows:
inverse Hill_two:
inverse Weibull:
inverse Logit:
inverse BCW:
inverse BCL:
inverse GL:
where is effect and
is the concentration.
Value
ecx |
a numeric vector of effect concentration(s) |
effvAbs |
absolute effect levels. Only for 'continuous' data with scaled effv. The corresponding absolute effect is calculated. |
References
Hill equation (biochemistry) http://en.wikipedia.org/wiki/Hill_equation_(biochemistry)
Reference to curveFit
Examples
## example 1
# calculate EC5 and EC50 of seven antibiotics on the photobacteria
model <- antibiotox$sgl$model
param <- antibiotox$sgl$param
effv <- c(0.05, 0.5)
ECx(model, param, effv = c(0.05, 0.50))
## example 2
# calculate EC5 and EC50 of four heavy metals and four ionic liquids on the MCF-7 cells
model <- cytotox$sgl$model
param <- cytotox$sgl$param
ECx(model, param, effv = c(0.05, 0.50), rtype = 'quantal')