Computes the number of cells in a histogram using the method of Wand (1994).
Usage
nclass.wand(x, level = 1)
Arguments
x
numeric vector of observations.
level
integer specifying the number of levels of functional estimation used in
the estimation. For details, see the help page of dpih from the package
KernSmooth.
Value
A numeric value specifying the number of cells for the histogram of x.
Details
nclass.wand calls dpih, and then computes the number of cells
corresponding to the optimal bin width returned by dpih.
References
Wand, M.P. (1997). Data-based choice of histogram bin width.
American Statistician, 51, 59--64.