ci.bc {NCStats}R Documentation

Construct a confidence interval from boot.case results.

Description

Constructs a non-parametric bootstrap confidence interval from boot.case (in the alr3 package) like results.

Usage

ci.bc(bc,conf.level=0.95)

Arguments

bc A vector or matrix containing parameter estimates in columns computed on many different bootstrap samples in rows.
conf.level A level of confidence as a proportion.

Details

This function simply finds the two quantiles that have the proportion (1-conf.level)/2 of the bootstrapped parameter estimates below and above. This is an approximate 100conf.level% confidence interval.

Value

If bc is a matrix then a matrix with as many rows as columns (i.e., parameter estimates) in bc and two columns of the quantiles that correspond to the approximate confidence interval will be returned. If bc is a vector then a vector with the two quantiles that correspond to the approximate confidence interval will be returned.

Author(s)

Derek H. Ogle, dogle@northland.edu

References

S. Weisberg (2005). Applied Linear Regression, third edition. New York: Wiley, Chapters 4 and 11.

See Also

boot.case in alr3.

Examples

## Not run, because boot.case takes a great deal of time:
## Should work if copied and pasted into console
## Not run: data(Ecoli)
## Not run: nl1 <- nls(cells~B1/(1+exp(B2+B3*days)),data=Ecoli,start=list(B1=6,B2=7.2,B3=-1.45))
## Not run: library(alr3)
## Not run: nl1.boot <- boot.case(nl1) # requires alr3
## Not run: ci.bc(nl1.boot,conf.level=0.90)

[Package NCStats version 0.0-12 Index]