smplot2 (version 0.2.5)

sm_statBlandAlt: Statistics for a Bland-Altman plot

Description

Bland-Altman plot is drawn to show measurement variability/reliabiilty of a task. This function requires two paired datasets (same length). It returns a list of difference (by element), mean, standard deviation of the difference, mean difference, upper and lower limits. These values are necessary to draw a Bland Altman plot.

The list returned from this function can be directly used as an argument for sm_bland_altman(), which draws a Bland-Altman plot using ggplot2.

Another output 'data' is a tibble with two columns: 1) Mean across each pair for each element (ex. a mean of the 1st element from the first set and 1st element from the second set), 2) Difference between each pair for every element. The output 'data' should be used as a argument for data in ggplot() when plotting.

Usage

sm_statBlandAlt(first, second)

Value

A list is returned, which has all numerical results that are relevant to drawing a Bland-Altman plot.

Arguments

first

Data from the first repetition/session

second

Data from the second repetition/session

Examples

library(smplot2)
library(tibble)

first <- rnorm(20)
second <- rnorm(20)
df <- as_tibble(cbind(first,second)) # requires library(tidyverse)
sm_statBlandAlt(df$first, df$second)