coef_diff_by_group {breathtestcore}  R Documentation 
Tabulates breath test parameter differences of groups
Description
Given a fit to 13C breath test curves, computes betweengroup confidence
intervals and pvalues, for examples of the half emptying time t50
,
with correction for multiple testing.
Usage
coef_diff_by_group(fit, mcp_group = "Tukey", reference_group = NULL, ...)
Arguments
fit 
Object of class 
mcp_group 
"Tukey" (default) for all pairwise comparisons, "Dunnett" for comparisons relative to the reference group. 
reference_group 
Used as the first group and as reference group for

... 
Not used 
Value
A tibble
of class coef_diff_by_group
with columns
 parameter
Parameter of fit, e.g.
beta, k, m, t50
 method
Method used to compute parameter.
exp_beta
refers to primary fit parametersbeta, k, m
.maes_ghoos
uses the method from Maes B D, Ghoos Y F, Rutgeerts P J, Hiele M I, Geypens B and Vantrappen G 1994 Dig. Dis. Sci. 39 S1046.bluck_coward
is the selfcorrecting method from Bluck L J C and Coward W A 2006 groups
Which pairwise difference, e.g
solid  liquid
 estimate
Estimate of the difference
 conf.low, conf.high
Lower and upper 95 A comparison is significantly different from zero when both estimates have the same sign.
 p.value
pvalue of the difference against 0, corrected for multiple testing
Examples
library(dplyr)
data("usz_13c")
data = usz_13c %>%
dplyr::filter( patient_id %in%
c("norm_001", "norm_002", "norm_003", "norm_004", "pat_001", "pat_002","pat_003")) %>%
cleanup_data()
fit = nls_fit(data)
coef_diff_by_group(fit)
fit = nlme_fit(data)
coef_diff_by_group(fit)
# TODO: Add example for Stan fit typecast to class \code{breathtestfit} to compute
# confidence intervals instead of credible intervals