exams.forge (version 1.0.10)

add_data: Vector Data Addition

Description

Adds data values to a given data vector x.

Usage

add_data(x, box, n = c(0, 1), range = c(0, 1))

Value

a data vector with new values

Arguments

x

numeric: data vector

box

character or numeric: a basic box is used

n

numeric: number of data values on the left, the right, or both sides of x (default: c(0,1))

range

numeric: determines the range where the additional data values will be drawn from (default: c(0,1))

Details

Based on the data x, or the range(box), a box is computed. The length of the box gives the multiplier for the range. Then a left and right interval, from which the additional values are drawn uniformly, is computed: \([left box value-range[2]*box length; left box value-range[1]*box length]\) (left interval) and \([right box value+range[1]*box length; right box value+range[2]*box length]\) (right interval).

For box, "boxplot" can be also used and quantile(x, c(0.25, 0.75), na.rm=TRUE) can be used instead of range(x, na.rm=TRUE).

n can be a single number which will add n data values at the right side of x. If n is a vector of length two, then n[1] data values will be added at the left side of x and n[2] data values will be added at the right side of x.

Examples

x <- rnorm(8)
# add one value to the right
add_data(x, "box", range=1.5)
add_data(x, "range", range=0.1)
add_data(x, "box", range=c(1.5, 3))
# add two values to the right
add_data(x, "range", n=2, range=0.1)
# add two values to the left and three to the right
add_data(x, "range", n=c(2,3), range=0.1)