denspr {siggenes} | R Documentation |
Estimates the density of a vector of observations by a Poisson regression fit to histogram counts.
denspr(x, n.interval = NULL, df = 5, knots.mode = TRUE, type.nclass = c("wand", "scott", "FD"))
x |
a numeric vector containing the observations for which the density should be estimated |
n.interval |
an integer specifying the number of cells for the histogram.
If NULL , n.interval is estimated by the method specified by
type.nclass |
df |
integer specifying the degrees of freedom of the natural cubic spline used in the Poisson regression fit |
knots.mode |
if TRUE the df - 1 knots are centered around the
mode and not the median of the density, where the mode is estimated by the
midpoint of the cell of the histogram that contains the largest number of
observations. If FALSE , the default knots are used in the function ns .
Thus, if FALSE the basis matrix will be generated by ns(x, df = 5) |
type.nclass |
character string specifying the procedure used to compute the
number of cells of the histogram. Ignored if n.interval is specified.
By default, the method of Wand (1994) with
level = 1 (see the help page of dpih in the package KernSmooth)) is used.
For the other choices, see nclass.scott |
A list consisting of
y |
a numeric vector of the same length as x containing the estimated density
for each of the observations |
center |
a numeric vector specifying the midpoints of the cells of the histogram |
counts |
a numeric vector of the same length as center composed of the number
of observations of the corresponding cells |
x.mode |
the estimated mode |
ns.out |
the output of ns |
type |
the method used to estimate the numbers of cells |
Holger Schwender,holger.schw@gmx.de
Efron, B., and Tibshirani, R. (1996). Using specially designed exponential families for density estimation. Annals of Statistics, 24, 2431–2461.
Wand, M.P. (1997). Data-based choice of histogram bin width. American Statistician, 51, 59–64.