rafalib (version 1.0.0)

maplot: Bland Altman plot aka MA plot

Description

Takes two vectors x and y and plots M=y-x versus A=(x+y)/2. If the vectors a more longer than length n the data is sampled to size n. A smooth curve is added to show trends.

Usage

maplot(x, y, n = 10000, subset = NULL, xlab = NULL, ylab = NULL, curve.add = TRUE, curve.col = 2, curve.span = 1/2, curve.lwd = 2, curve.n = 2000, ...)

Arguments

x

a numeric vector

y

a numeric vector

n

a numeric value. If length(x) is larger than n, the x and y are sampled down.

subset

index of the points to be plotted

xlab

a title for the x axis

ylab

a title for the y axis

curve.add

if TRUE a smooth curve is fit to the data and displayed. The function loess is used to fit the curve.

curve.col

a numeric value that determines the color of the smooth curve

curve.span

is passed on to loess as the span argument

curve.lwd

the line width for the smooth curve

curve.n

a numeric value that determines the sample size used to fit the curve. This makes fitting the curve faster with large datasets

...

further arguments passed to plot

Examples

n <- 10000
signal <- runif(n,4,15)
bias <- (signal/5 - 2)^2
x <- signal + rnorm(n)
y <- signal + bias + rnorm(n)
maplot(x,y)