Given a fit to 13C breath test curves, computes absolute values and their confidence intervals of parameters, e.g. of the half emptying time t50. Generic S3 method for class breathtestfit.

coef_by_group(fit, ...)

Arguments

fit

Object of class breathtestfit, for example from nlme_fit, nls_fit or stan_fit

...

Not used

Value

A tibble of class coef_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 parameters beta, 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 S104-6. bluck_coward is the self-correcting method from Bluck L J C and Coward W A 2006

group

Grouping parameter of the fit, e.g. patient, normal, liquid, solid

estimate

Parameter estimate

conf.low, conf.high

Lower and upper 95 estimate.

diff_group

Letters a, b, c indicate that parameter would be in mutually significantly different groups. Letter combinations like ab or abc indicated that this parameter is not significantly different from the given other groups in a Tukey-corrected pairwise test.

Examples

library(dplyr)
#> #> Attache Paket: 'dplyr'
#> The following objects are masked from 'package:stats': #> #> filter, lag
#> The following objects are masked from 'package:base': #> #> intersect, setdiff, setequal, union
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_by_group(fit)
#> # A tibble: 27 x 7 #> parameter method group estimate conf.low conf.high diff_group #> <chr> <chr> <chr> <dbl> <dbl> <dbl> <chr> #> 1 beta exp_beta liquid_normal 2.09 1.73 2.45 a #> 2 beta exp_beta solid_normal 2.23 1.92 2.54 a #> 3 beta exp_beta solid_patient 2.11 1.75 2.48 a #> 4 deviance exp_beta liquid_normal 16.8 -20.1 53.8 ab #> 5 deviance exp_beta solid_normal 2.72 -33.4 38.8 a #> 6 deviance exp_beta solid_patient 68.9 27.2 111. b #> 7 k exp_beta liquid_normal 0.0131 0.0106 0.0156 b #> 8 k exp_beta solid_normal 0.00963 0.00737 0.0119 a #> 9 k exp_beta solid_patient 0.00704 0.00444 0.00965 a #> 10 m exp_beta liquid_normal 36.5 22.6 50.4 b #> # ... with 17 more rows
fit = nlme_fit(data) coef_by_group(fit)
#> # A tibble: 24 x 7 #> parameter method group estimate conf.low conf.high diff_group #> <chr> <chr> <chr> <dbl> <dbl> <dbl> <chr> #> 1 beta exp_beta liquid_normal 2.09 1.89 2.28 a #> 2 beta exp_beta solid_normal 2.17 2.00 2.35 a #> 3 beta exp_beta solid_patient 2.20 2.01 2.40 a #> 4 k exp_beta liquid_normal 0.0131 0.0112 0.015 b #> 5 k exp_beta solid_normal 0.00937 0.00764 0.0111 a #> 6 k exp_beta solid_patient 0.00759 0.00559 0.00960 a #> 7 m exp_beta liquid_normal 36.3 23.1 49.6 b #> 8 m exp_beta solid_normal 20.8 7.71 33.9 a #> 9 m exp_beta solid_patient 31.9 16.7 47.0 ab #> 10 t50 bluck_coward liquid_normal 29.7 19.9 39.5 a #> # ... with 14 more rows