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Last data update: 2014.03.03

R: R2 values with corresponding probability density and...

pcdfs

R Documentation

R2 values with corresponding probability density and cumulative density functions.

Description

This function builds a data frame of all possible R2 values over its range of 0 to 1, with corresponding values of probability (pdf) and cumulative probability (cdf) for a given number of degrees of freedom. R2 is divided uniformly over its range into bins whose width is determined by the number of decimal places chosen (default=3). The number of samples is determined by order (10^order). Values of the cumulative density function (cdf) are used to calculate the baseline noise level, R2p.

Usage

pcdfs(dof, order = 6, ndecimals = 3, dist = "normal", par1 = 0, par2 = 1)

Arguments

`dof`	an integer greater than 1
`order`	a positive number used to set the order of magnitide of the number of samples (default is 6)
`ndecimals`	a positive integer describing the number of decimal places desired in the results
`dist`	a character string identifying the noise distribution. The current list of possible distributions is, 'normal', 'uniform', 'lognormal', 'poisson' and 'binomial'.
`par1`	one of two parameters used to define the noise distribution For 'normal', par1 = mean, For 'uniform', par1 = min, For 'lognormal', par1 = logmean, For 'poisson', par1=lambda, For 'binomial', par1=size
`par2`	the second of two parameters used to define the noise distribution For 'normal', par2 = std dev, For 'uniform', par2 = max, For 'lognormal', par2 = log std dev, For 'poisson', par2=(not used), For 'binomial', par2=probability

Value

pcdfs returns a data frame with columns "R2", "pdf" and "cdf". R2 is the full range of values that R2 can possibly have (from 0 to 1) divided by 10^bw where bw (bin width). binwidth is determined by ndecimals so 10^bw = 10^(-ndecimals). pdf is the probability density function – the probability of obtaining a specific range of values of R2 corresponding to one of the bins. Values range from 0 to 1. cdf is the cumulative pdf. Values of cdf also range from 0 to 1.

Author(s)

Joseph G. Kreke, PhD

Examples

	R2df <- pcdfs(dof=8, order=6, ndecimals=3, dist="uniform")
	R2df <- pcdfs(5)