heter.QRank {QRank}

Heterogeneity index for "QRank"

Description

Calculate the heterogeneity index of quantile regression coefficients at multiple quantile levels. It measures the variation of the quantile coefficients across quantile levels.

heterogeneity=log(sd(\beta)/abs(mean(\beta)))

where \beta is the vector of quantile regression coefficients at multiple quantile levels.

Usage

heter.QRank(object, newtaus=NULL)

Arguments

object

Object returned from "QRank"

newtaus

a vector of quantile levels based on which heterogeneity index are calculated. Default is NULL, in which case the quantile levels inherited from "QRank" will be used.

Value

heterogeneity index

one hetergeneity index

See Also

QRank

Examples

# continuted from "QRank"

taus=c( 0.25, 0.5, 0.75)
q = QRank(gene=y, snp=x, cov=z, tau=taus)  
heter.QRank(q) # default uses taus inherited from "QRank"
# - output
#Heterogeneity index:
#[1] 2.474184
heter.QRank(q,newtaus = 1:9/10) # calculate based on new taus values
# - output
#Heterogeneity index:
#[1] 2.69242