blandAltman: Bland-Altman plot.

In tsieger/tsiMisc: Miscelaneous utility functions, mostly related to exploratory statistical analysis

Bland-Altman plot.

Description

The Bland-Altman plot (AKA Tukey mean-difference plot) is a graphical tool to measure agreement between two estimates of a single variables methods.

Usage

blandAltman(x1, x2, xlab = "Average", 
    ylab = "Difference", 
    alpha = 0.05)

Arguments

x1	the first estimate
x2	the second estimate
xlab	a label of x-axis on which the mean of the two estimates is plotted
ylab	a label of y-axis on which the difference between the two estimates is plotted
alpha	significance level of the confidence interval

Details

Code taken from http://rstats.tiddlyspot.com/#Bland-Altman and updated slightly.

Value

a list of 'mean' (the of the two estimates), 'diff' (the diff of the estimates, 'se' (the standard error of the differences), and the '1-alpha/2' confidence intervals for the 'mean +/- 2 * SD of diffs' given as 'lower' and 'upper'

Author(s)

Tomas Sieger

References

Bland JM, Altman DG (1986) _Statistical methods for assessing agreement between two methods of clinical measurement.__ Lancet 327 (8476): 30710.

Examples

n<-20
x<-rnorm(n)
x1<-x+rnorm(n,0,.1)
x2<-x+rnorm(n,0,.1)
blandAltman(x1,x2)

tsieger/tsiMisc documentation built on Oct. 10, 2023, 10:24 p.m.