MFBoot: Bootstrap MF CI

In MF: Mitigated Fraction

Description

Estimates bootstrap confidence intervals for the mitigated fraction.

Usage

  MFBoot(formula, data, compare = c("con", "vac"), b = 100,
    B = 100, alpha = 0.05, hpd = TRUE, bca = FALSE,
    return.boot = FALSE, trace.it = FALSE)

Arguments

formula	Formula of the form y ~ x, where y is a continuous response and x is a factor with two levels
data	Data frame
compare	Text vector stating the factor levels - compare[1] is the control or reference group to which compare[2] is compared
b	Number of bootstrap samples to take with each cycle
B	Number of cycles, giving the total number of samples = B * b
alpha	Complement of the confidence level
hpd	Estimate highest density intervals? Default TRUE.
bca	Estimate BCa intervals? Default FALSE.
return.boot	Save the bootstrap sample of the MF statistic? Default FALSE.
trace.it	Verbose tracking of the cycles? Default FALSE.

Details

Resamples the data and produces bootstrap confidence intervals. Equal tailed intervals are estimated by the percentile method. Highest density intervals are estimated by selecting the shortest of all possible intervals. For BCa intervals, see Efron and Tibshirani section 14.3.

Value

a mfboot-class data object

Author(s)

David Siev [e-mail]

References

Siev D. (2005). An estimator of intervention effect on disease severity. Journal of Modern Applied Statistical Methods. 4:500–508

Efron B, Tibshirani RJ. An Introduction to the Bootstrap. Chapman and Hall, New York, 1993.

See Also

mfboot-class

Examples

MFBoot(lesion~group, calflung)

# 10000 bootstrap samples
# 95% confidence interval
#
# Comparing vac to con
#                 observed median  lower  upper
# Equal Tailed        0.44 0.4464 0.1360 0.7056
# Highest Density     0.44 0.4464 0.1456 0.7088

Example output

10000 bootstrap samples
 95% confidence interval


Comparing vac to con 
                observed median  lower  upper
Equal Tailed        0.44 0.4464 0.1360 0.7056
Highest Density     0.44 0.4464 0.1424 0.7088

MF documentation built on May 2, 2019, 1:46 p.m.