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Last data update: 2014.03.03

R: This function plots the histogram and a fitted (GAMLSS...

histDist

R Documentation

This function plots the histogram and a fitted (GAMLSS family) distribution to a variable

Description

This function fits constants to the parameters of a GAMLSS family distribution and them plot the histogram and the fitted distribution.

Usage

histDist(y, family = NO, freq = NULL, 
        density = FALSE, nbins = 10, xlim = NULL, 
        ylim = NULL, main = NULL, xlab = NULL, 
        ylab = NULL, data = NULL, ...)

Arguments

`y`	a vector for the response variable
`family`	a `gamlss.family` distribution
`freq`	the frequencies of the data in `y` if exist. `freq` is used as `weights` in the `gamlss` fit
`density`	default value is FALSE. Change to TRUE if you would like a non-parametric density plot together with the parametric fitted distribution plot (for continuous variable only)
`nbins`	The suggested number of bins (argument passed to `truehist()` of package MASS). Either a positive integer, or a character string naming a rule: "Scott" or "Freedman-Diaconis" or "FD". (Case is ignored.)
`xlim`	the minimum and the maximum x-axis value (if the default values are out of range)
`ylim`	the minimum and the maximum y-axis value (if the default values are out of range)
`main`	the main title for the plot
`xlab`	the label in the x-axis
`ylab`	the label in the y-axis
`data`	the data.frame
`...`	for extra arguments to be passed to the `gamlss` function

Details

This function first fits constants for each parameters of a GAMLSS distribution family using the gamlss function and them plots the fitted distribution together with the appropriate plot according to whether the y variable is of a continuous or discrete type. Histogram is plotted for continuous and barplot for discrete variables. The function truehist of Venables and Ripley's MASS package is used for the histogram plotting.

Value

returns a plot

Author(s)

Mikis Stasinopoulos

References

Rigby, R. A. and Stasinopoulos D. M. (2005). Generalized additive models for location, scale and shape,(with discussion), Appl. Statist., 54, part 3, pp 507-554.

Stasinopoulos D. M., Rigby R.A. and Akantziliotou C. (2006) Instructions on how to use the GAMLSS package in R. Accompanying documentation in the current GAMLSS help files, (see also http://www.gamlss.org/).

Stasinopoulos D. M. Rigby R.A. (2007) Generalized additive models for location scale and shape (GAMLSS) in R. Journal of Statistical Software, Vol. 23, Issue 7, Dec 2007, http://www.jstatsoft.org/v23/i07.

Examples

data(abdom)
histDist(y,family="NO", data=abdom)
# use the ylim 
histDist(y,family="NO", ylim=c(0,0.005), data=abdom)
# bad fit use PE
histDist(y,family="PE",ymax=0.005, data=abdom)
# discere data counts 
#  Hand at al. p150  Leptinotarsa decemlineata
y <- c(0,1,2,3,4,6,7,8,10,11)
freq <- c(33,12,5,6,5,2,2,2,1,2) 
histDist(y, "NBI", freq=freq)
# the same as 
histDist(rep(y,freq), "NBI")