fast (version 0.51)

sensitivity: Calculate sensitivity according to the FAST algorithm

Description

This function calculates the sensitivity from a series of model outputs (x) according to the FAST alogrithm.

Usage

sensitivity(x, numberf, order = 4, make.plot = FALSE, plot.max = FALSE, include.total.variance = FALSE, plot.main = "", cukier=TRUE, names=paste(sep="", "P", 1:numberf) )

Arguments

x

A vector of model outputs where parameters vary between runs according to the fast algorithm.

numberf

Number of parameters varied.

order

Order of parameter frequency independence (see Cukier)

make.plot

plot the Fourier spectrum?

plot.max

xmax in the spectrum

include.total.variance

include the sum of all variances in the result list.

plot.main

Title for the plot

names

A vector of parameter names.

cukier

boolean: Calculate FAST-parameters according to Cukier 1975 or McRae 1982

Value

• A list of the partial variance accounted for by each parameter.

References

CUKIER, R. I.; SCHAIBLY, J. H. & SHULER, K. E. Study Of Sensitivity Of Coupled Reaction Systems To Uncertainties In Rate Coefficients .3. Analysis Of Approximations Journal Of Chemical Physics, 1975 , 63 , 1140-1149

McRae, G.; Tilden, J. & Seinfeld, J. Global sensitivity analysis - a computational implementation of the Fourier amplitude sensitivity test (FAST) Comput. Chem. Eng., 1982 , 6 , 15-25

See Also

S, fast

Examples

example_model1<-function(p,x){
   return(p[1]*x+p[2]*(1-x))
}
paras<-fast_parameters(min=c(0,0,0),max=c(1,2,2))
paras
model_results <- apply(paras, 1, example_model1, x=0.5)
model_results
sensitivity <- sensitivity(x=model_results, numberf=3, make.plot=TRUE)
sensitivity