# ImmunogG: Immunoglobulin G Data In Brq: Bayesian Analysis of Quantile Regression Models

## Description

This data set comprises the serum concentration (grams per litre) of immunoglobulin G in 298 children aged from 6 months to 6 years and is discussed in detail by Isaacs et al. (1983) and used in Keming et al. (2003).

## Usage

 `1` ```data("ImmunogG") ```

## Format

A data frame with 298 observations on the following 2 variables.

`IgG`

The serum concentration (grams per litre) of immunoglobulin G

`Age`

Age of children in years.

## Source

[1] Isaacs, D., Altman, D. G., Tidmarsh, C. E., Valman, H. B. and Webster, A. D. B. (1983) Serum Immunoglobin concentrations in preschool children measured by laser nephelometry: reference ranges for IgG, IgA and IgM. J. Clin. Path., 36, 1193-1196.

## References

[1] Yu, K., Lu, Z., & Stander, J. (2003). Quantile regression: applications and current research areas. Journal of the Royal Statistical Society:Series D (The Statistician), 52(3), 331-350.

## Examples

 ``` 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17``` ```data(ImmunogG) attach(ImmunogG) y=IgG x=Age X=cbind(x, x^2) plot(Age,IgG) plot(Age,IgG, main="Quantile Regression Fit", cex=.5, col="gray") for (i in 1:5) { if (i==1) p = .05 if (i==2) p = .25 if (i==3) p = .50 if (i==4) p = .75 if (i==5) p = .95 fit = Brq(y~X,tau=p,runs=400, burn=100) # Note: runs =11000 and burn =1000 curve(fit\$coef[1]+fit\$coef[2]*x+fit\$coef[3]*x^2,col=i,add=TRUE) } ```

Brq documentation built on July 1, 2020, 7:07 p.m.