snap: Coerce Values to Nearest of Candidates

In metrumrg: Pharmacometric Tools for Data Preparation, Modeling, Simulation, and Reporting

Description

For each value in a numeric vector, return the closest match from a vector of candidate values.

Usage

snap(x, rule = 1, left = TRUE, ...)

Arguments

x	numeric
rule	a vector of (finite numeric) candidates, or a single value giving candidate interval on the real number line
left	whether to return the lesser of two equidistant candidates
...	ignored

Details

If rule is scalar, it must be positive; a rule will be constructed as a sequence of rule-spaced values that includes zero and includes values at least as extreme as the extremes of x. In some sense, this function is the complement to cut: whereas in cut one specifies the "breaks", with snap one specifies a set of "attractors" (breaks are the implied midpoints); both functions map their primary argument to a (possibly) smaller set of values.

Value

numeric

Note

If length of x is zero, it is returned unmodified. If length of rule is zero, value is all NA.

Author(s)

Tim Bergsma

References

http://metrumrg.googlecode.com

See Also

• findInterval

• cut

Examples

snap(c(0.0, 1.0, 1.2, 2.0, 2.9, 3))
snap(-10:10, 0.3)
xyplot(conc~Time,data=Theoph,groups=Subject)
times <- c(0,.25,.5,1,2,4,5,7,9,12,24)
xyplot(conc~snap(Time,times),data=Theoph,groups=Subject)
snap(c(3,NA,5), c(2,4,6))
snap(c(3,NA,5), numeric(0))

metrumrg documentation built on May 2, 2019, 5:55 p.m.