R Graphical Manual

Browse All

Last data update: 2014.03.03

R: Mode of a Unimodal Distribution

distMode

R Documentation

Mode of a Unimodal Distribution

Description

Function to calculate the mode of a unimodal distribution which is specified by the root of the density function name and the corresponding parameters.

Usage

distMode(densFn, param = NULL, ...)

Arguments

`densFn`	Character. The name of the density function for which the mode is required.
`param`	Numeric. A vector giving the parameter values for the distribution specified by `densFn`. If no `param` values are specified, then the default parameter values of each distribution are used instead.
`...`	Passes arguments to `optimize`. In particular, the parameters of the distribution.

Details

The name of the unimodal density function must be supplied as the characters of the root for that density (e.g. norm, ghyp). The particular unimodal distribution being considered is specified by the value of the argument param, or for base R distributions by specification in the ... arguments.

Value

The mode is found by a numerical optimization using optimize.

Author(s)

David Scott d.scott@auckland.ac.nz, Joyce Li xli053@aucklanduni.ac.nz

Examples

normRange <- distCalcRange("norm", tol = 10^(-7), mean = 4, sd = 1)
curve(dnorm(x, mean = 4, sd = 1), normRange[1], normRange[2])
abline(v = distMode("norm", mean = 4, sd = 1), col = "blue")

Results


R version 3.3.1 (2016-06-21) -- "Bug in Your Hair"
Copyright (C) 2016 The R Foundation for Statistical Computing
Platform: x86_64-pc-linux-gnu (64-bit)

R is free software and comes with ABSOLUTELY NO WARRANTY.
You are welcome to redistribute it under certain conditions.
Type 'license()' or 'licence()' for distribution details.

R is a collaborative project with many contributors.
Type 'contributors()' for more information and
'citation()' on how to cite R or R packages in publications.

Type 'demo()' for some demos, 'help()' for on-line help, or
'help.start()' for an HTML browser interface to help.
Type 'q()' to quit R.

> library(DistributionUtils)
Loading required package: RUnit
> png(filename="/home/ddbj/snapshot/RGM3/R_CC/result/DistributionUtils/distMode.Rd_%03d_medium.png", width=480, height=480)
> ### Name: distMode
> ### Title: Mode of a Unimodal Distribution
> ### Aliases: distMode
> ### Keywords: distribution univar
> 
> ### ** Examples
> 
> normRange <- distCalcRange("norm", tol = 10^(-7), mean = 4, sd = 1)
> curve(dnorm(x, mean = 4, sd = 1), normRange[1], normRange[2])
> abline(v = distMode("norm", mean = 4, sd = 1), col = "blue")
> 
> 
> 
> 
> 
> dev.off()
null device 
          1 
>