cenanova | R Documentation |
Performs a parametric test of differences in means between groups of censored data, followed by a parametric Tukey's multiple comparison test.
cenanova(x1, x2, group, LOG = TRUE, printstat = TRUE)
x1 |
The column of data values plus detection limits |
x2 |
The column of indicators, where 1 (or |
group |
Grouping or factor variable. Can be either a text or numeric value indicating the group assignment. |
LOG |
Indicator of whether to compute tests in the original units, or on their logarithms. The default is to use the logarithms ( |
printstat |
Logical |
Test is computed using Maximum Likelihood Estimation. When a gaussian distribution model is used (LOG=FALSE) modeled values may fall below zero, producing unreal p-values (often lower than they should be). Because of this, testing in log units is preferable and is the default.
Returns the Maximum Likelihood Estimation (MLE) comparison results including Chi-Squared value, degrees of freedom and p-value
of the test. Test assumes log-normal(LOG=TRUE
) or normal(LOG=FALSE
) distribution of residuals from group means.
Tukey's multiple comparison p-values of pairwise differences in group means are also printed.
Group Names of groups (NOTE: == 0
indicates null hypothesis of "equals zero").
Estimate
Estimated difference between group means.
Std. Error
Standard error of estimate.
z value
Test statistic.
Pr(>|z|)
P-values for test that difference in means equals zero.
Helsel, D.R., 2011. Statistics for Censored Environmental Data using Minitab and R, 2nd ed. John Wiley & Sons, USA, N.J.
#' @examples data(PbHeron) cenanova(PbHeron$Liver,PbHeron$LiverCen,PbHeron$DosageGroup)
cenanova(PbHeron$Liver,PbHeron$LiverCen,PbHeron$DosageGroup,LOG=FALSE)
survival::survreg
Add the following code to your website.
For more information on customizing the embed code, read Embedding Snippets.