Iterated conditional expectation kernel density estimation
using a local constant. The bandwidth is assumed fixed. (See
the example for a way to get a quick ballpark estimate of the bandwidth.)
The gaussian, epanechnikov and biweight kernels can be used. Note
that the bandwidth estimate would have to be adjusted before using
with epanechnikov or biweight.
A matrix with two columns, consisting of left and right
endpoints of the interval data
h
A scalar bandwidth
f
An initial estimate of the density at a sequence of grid
points (optional; if this is used, do not specify m)
m
The number of (equally-spaced) grid points at which
the density is to be estimated
n.iterations
The maximum number of iterations allowed
x1
The left-most grid point (optional)
xm
The right-most grid point (optional)
right.limit
For right-censored data, the value to be
used as an artificial right endpoint for the intervals
kernel
character argument indicated choice of kernel; current
choices are "gaussian", "epanechnikov", "biweight"
old
logical value, indicating whether denominators in
conditional expectation calculation
should use the previous value of the density estimate.
Value
An object of class IC
Author(s)
W.J. Braun
References
Braun, J., Duchesne, T. and Stafford, J.E. (2005)
Local likelihood density estimation for interval censored
data. Canadian Journal of Statistics 33: 39-60.
Examples
tmp <- apply(ICHemophiliac, 1, mean)
h <- try(dpik(tmp), silent=T) # dpik() will work if KernSmooth is loaded
if (class(h) !="numeric" ) h <- .9 # this makes the example work
# if KernSmooth is not loaded
estimate <- ickde(ICHemophiliac, m=200, h=h)
plot(estimate, type="l")
Results
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> library(ICE)
Loading required package: KernSmooth
KernSmooth 2.23 loaded
Copyright M. P. Wand 1997-2009
> png(filename="/home/ddbj/snapshot/RGM3/R_CC/result/ICE/ickde.Rd_%03d_medium.png", width=480, height=480)
> ### Name: ickde
> ### Title: Interval-Censored Kernel Density Estimation
> ### Aliases: ickde
> ### Keywords: models
>
> ### ** Examples
>
> tmp <- apply(ICHemophiliac, 1, mean)
> h <- try(dpik(tmp), silent=T) # dpik() will work if KernSmooth is loaded
> if (class(h) !="numeric" ) h <- .9 # this makes the example work
> # if KernSmooth is not loaded
> estimate <- ickde(ICHemophiliac, m=200, h=h)
> plot(estimate, type="l")
>
>
>
>
>
> dev.off()
null device
1
>