adjusted bootstrap confidence intervals (BCa) with parametric bootstrap in boot package adjusted bootstrap confidence intervals (BCa) with parametric bootstrap in boot package r r

adjusted bootstrap confidence intervals (BCa) with parametric bootstrap in boot package


After looking at the boot.ci page I decided to use a boot-object constructed along the lines of an example in Ch 6 of Davison and Hinkley and see whether it generated the errors you observed. I do get a warning but no errors.:

require(boot) lmcoef <- function(data, i){      d <- data[i, ]      d.reg <- lm(y~x, d)      c(coef(d.reg)) }lmboot <- boot(d, lmcoef, R=999)m1boot.ci(lmboot, index=2)   # I am presuming that the interest is in the x-coefficient#----------------------------------BOOTSTRAP CONFIDENCE INTERVAL CALCULATIONSBased on 999 bootstrap replicatesCALL : boot.ci(boot.out = lmboot, index = 2)Intervals : Level      Normal              Basic         95%   (-0.0210,  0.0261 )   (-0.0236,  0.0245 )  Level     Percentile            BCa          95%   (-0.0171,  0.0309 )   (-0.0189,  0.0278 )  Calculations and Intervals on Original ScaleWarning message:In boot.ci(lmboot, index = 2) :  bootstrap variances needed for studentized intervals