Number of evaluations for the brute
force inversion of the expert cdf.
Details
The inverse of the distribution function is formed by evaluating
the distribution function at nPoints points and interchanging the
role of dependent and independent variable when building an function
interpolating the data (using splinefun with "monoH.FC"
option). Note that there are also direct ways of inverting a B-spline
function, which however turned out to be less efficient for our purposes.
Value
A numeric vector containing pseudo-random variates from the
expert's density.
Author(s)
Bjoern Bornkamp
References
Bornkamp, B. and Ickstadt, K. (2009). A Note on B-Splines for
Semiparametric Elicitation. The American Statistician, 63, 373–377
See Also
SEL, splinefun
Examples
## bimodal example
x2 <- c(0.1, 0.2, 0.5, 0.8, 0.9)
y2 <- c(0.2, 0.4, 0.45, 0.85, 0.99)
fit1 <- SEL(x2, y2, Delta=0.05, d = 4, inknts = x2)
fit2 <- SEL(x2, y2, Delta=0.05, d = 15, N = 0)
comparePlot(fit1, fit2, superpose = TRUE)
## sample from SEL object
xxx <- rvSEL(50000, fit1)
hist(xxx, breaks=100, freq=FALSE)
curve(predict(fit1, newdata=x), add=TRUE)
Results
R version 3.3.1 (2016-06-21) -- "Bug in Your Hair"
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> library(SEL)
Loading required package: splines
Loading required package: quadprog
Loading required package: lattice
> png(filename="/home/ddbj/snapshot/RGM3/R_CC/result/SEL/rvSEL.Rd_%03d_medium.png", width=480, height=480)
> ### Name: rvSEL
> ### Title: Simulate from the expert's distribution
> ### Aliases: rvSEL
> ### Keywords: misc
>
> ### ** Examples
>
> ## bimodal example
> x2 <- c(0.1, 0.2, 0.5, 0.8, 0.9)
> y2 <- c(0.2, 0.4, 0.45, 0.85, 0.99)
>
> fit1 <- SEL(x2, y2, Delta=0.05, d = 4, inknts = x2)
> fit2 <- SEL(x2, y2, Delta=0.05, d = 15, N = 0)
> comparePlot(fit1, fit2, superpose = TRUE)
>
> ## sample from SEL object
> xxx <- rvSEL(50000, fit1)
> hist(xxx, breaks=100, freq=FALSE)
> curve(predict(fit1, newdata=x), add=TRUE)
>
>
>
>
>
> dev.off()
null device
1
>