smartjitter {hamlet}

Smart jittering function for deterministic shifting of overlapping values

Description

This function takes in a vector of measurements and computes overlapping bins of observations, and applies a jittering function within each overlapping bin.

Usage

smartjitter(x, q = seq(from = 0, to = 1, length.out = 10), type = 1, 
amount = 0.1, jitterfuncs = list(function(n) {
    (1:n)/(1/amount)
}, function(n) {
    (((-1)^c(0:(n - 1))) * (0:(n - 1)))/(1/amount)
}), jits = jitterfuncs[[type]])

Arguments

x

The values that should be jittered. Notice that these are used to determine which are overlapping, and should not be though of as x-axis positions (see example).

q

Probability quantiles where the ends of the bins should be placed

type

Type of jittering, by default it is used to choose which element (1 or 2) of the list of jittering functions is chosen as the final jittering function. Customized functions may be provided to the jitterfuncs-parameter.

amount

Amount of jittering (here deterministic shifting) for the jittering function

jitterfuncs

List of possible jittering functions for n overlapping values. The jittering function at list position 'type' is chosen

jits

Final jittering function from the jitterfuncs-list

Details

The smart jittering is applied to the x-parameter values, and returns a vector of shifting amounts per each observation. Notice that in the typical case, parameter 'x' are the desired response values e.g. among the y-axis, and the returned value of smartjitter are the amounts of jittering done on the x-axis of a plot.

Value

The function returns a vector of values with same length as x. The values in this vector indicate what should be the shifting per each observation, if the observations should be jittered along an another axis.

Author(s)

Teemu Daniel Laajala <[e-mail]>

Examples

data(vcapwide)

plot.new()
plot.window(xlim=extendrange(c(0,1)), ylim=extendrange(vcapwide[,"PSAWeek4"]))
y1 <- vcapwide[vcapwide[,"CastrationDate"]=="100413","PSAWeek4"]
y2 <- vcapwide[vcapwide[,"CastrationDate"]=="170413","PSAWeek4"]
points(x=0+smartjitter(y1, type=2, amount=0.02), y=y1)
points(x=1+smartjitter(y2, type=2, amount=0.02), y=y2)
axis(1, at=c(0,1), labels=c("10.04.13", "17.04.13"))
axis(2); box()
title(ylab="PSA at week 4", xlab="Castration batches")