var_tvv: Analysis of variance
In ikoenemund/blandxtr: Advanced Bland Altman analysis for method comparison

var_tvv executes analysis of variance for quantities measured with true value varying (includes standard and modified version)

1	var_tvv(n, n_obs, d, d_a, bias_alt, output_subjects, output_measurements)

`n`	number of subjects
`n_obs`	number of observations
`d`	mean of all differences
`d_a`	modified mean of all differences
`bias_alt`	set TRUE for alternative calculation of bias (small within-subject variance) and its variance, set FALSE for standard calculation of bias (small between-subjects variance) and its variance
`output_subjects`	data.table containing subject ID and number of measurements of each subject (m_i)
`output_measurements`	data.table from `basic_variables`-function

A list with the following elements is returned

wsv within-subject variance
bsv between-subjects variance
bsv_mod modified between-subjects variance
wsv_mod modified within-subject variance
var_d variance of mean of all differences
sd_d standard deviation of all differences
var_var_d variance of the variance of mean of all differences
var_d_mod modified variance of mean of all differences
sd_d_mod modified standard deviation of all differences
var_var_d_mod modified variance of the variance of mean of all differences
tau if tau < 1/3 use unmodified analysis of variance, if tau > 1/3 look at tau_mod
tau_mod look at tau first, if tau_mod < 1/3 use unmodified analysis of variance, if tau_mod > 1/3 use modified analysis of variance
se_sd_d standard error of sd of all differences
se_sd_d_mod standard error of modified sd of all differences
se_bsv standard error of between-subjects variance
se_bsv_mod standard error of modified between-subjects variance
se_wsv standard error of within-subject variance
se_wsv_mod standard error of modified within-subject variance
lambda helper variable for calculation of between-subjects variance, see Olofsen et al. 2015
lambda_mod helper variable for calculation of modified between-subjects variance, see Olofsen et al. 2015