enzyme {multimode}

Blood enzymatic activity

Description

This dataset concerns the distribution of enzymatic activity in the blood, for an enzyme involved in the metabolism of carcinogenic substances.

Usage

data(enzyme)

Format

enzyme includes the values of the urinary metabolic ratio of 5–acetylamino–6–formylamino–3–methyluracil to 1–methylxanthine (AFMU/1X) after oral administration of caffeine.

Details

This is a classic example for determining the number of modes.

Source

Obtained from the Supplementary material of Richardson and Green (1997), available in http://www.stats.bris.ac.uk/~peter/mixdata.

References

Bechtel, Y. C., Bonaiti-Pellie, C., Poisson, N., Magnette, J. and Bechtel, P. R. (1993). A population and family study N–acetyltransferase using caffeine urinary metabolites. Clinical Pharmacology and Therapeutics, 54, 134–141.

Richardson, S. and Green, P. J. (1997). On Bayesian analysis of mixtures with unknown number of components (with discussion). Journal of the Royal Statistical Society, Series B, 59, 731–792.

Examples

data("enzyme")
# It can be seen that there are two groups in this dataset
# Via exploratory tools
sizer(enzyme,bws=c(0.03,1))
modetree(enzyme,bws=c(0.02,1),logbw=TRUE,addplot=TRUE,col.lines="white")
#Via mode testing
modetest(enzyme)
## Not run: 
modetest(enzyme,mod0=2)

## End(Not run)