exmplot: Excess Mass Lambda Plot

In ExcessMass: Excess Mass Calculation and Plots

Excess Mass Lambda Plot

Description

Produces an excess mass lambda plot and calculates the maximal excess mass difference achieved by allowing for an additional mode.

Usage

exmplot(xdata, M=1, CutOff=1, steps=50, Lambda=NULL)

Arguments

xdata	data in form of a vector
M	the maximal number of modes
CutOff	determines the cut off value and hence the level up to which the λs are calculated
steps	number of different λs which are calculated / drawn
Lambda	allows specifying an own vector of λs

Details

CutOff should not be set too small or too large, as this results in meaningless graphs. The excess mass for several λs can be calculated by specifying the Lambda.

Value

An Excess Mass Lambda plot is produced. The lines in the plot are sorted by the maximal number of modes from left to right, due to the monotonicity of the excess mass in M.

max_dist	The i. entry is the maximal distance of the excess mass by allowing for up to i+1 instead of i modes
max_dist_Lambda	Shows the λ at which the maximal excess mass difference is achieved

Author(s)

Marc-Daniel Mildenberger [e-mail], based on earlier code from Dr. Guenther Sawitzki [e-mail]

References

Muller, D. W. and Sawitzki, G., 09.1991, "Excess Mass Estimates and Tests for Multimodality", Journal of the American Statistical Association , Vol. 86, No. 415, pp. 738–746, http://www.jstor.org/stable/2290406

See Also

excessm, exmsilhouette, mexmsilhouette

Examples

library(MASS)
attach(geyser)

##calculating the maximal excess mass difference for duration of 'Old Faithful Geyser' for M=3
exmplot(duration, M=3)

##Plotting the excess mass against lambda for modes 1-5, 
##increase CutOff value, double the number of steps
exmplot(duration, M=5, CutOff=1.2, steps=100)

##Specifying Lambda
Lambda=seq(.0,0.5,0.005)
exmplot(duration, M=7, Lambda=Lambda)

ExcessMass documentation built on June 14, 2022, 1:06 a.m.