This selects some values of a variable and creates a new "focal vector"
from them. Can use one "divider" algorithm, to be selected by name.
Usage
focalVals(x, divider = "quantile", n = 3)
Arguments
x
The input variable may be numeric or a factor.
divider
Either a quoted string name of an algorithm or a
function. Default = "quantile" for numeric variables, "table" for
factors. Other valid values: "seq" for an evenly spaced sequence
from minimum to maximum, "std.dev." for a sequence that has the
mean at the
n
Desired number of focal values.
Value
A named vector of focal values selected from a variable. The
values of the names should be informative and useful for plotting or
other diagnostic work.
Details
This is a "wrapper" (or convenience) function that re-directs work
to other functions. The functions that do the work to select the
focal values for types ("table", "quantile", "std.dev.", "seq") are
(cutByTable(), cutByQuantile(), cutBySD(), and plotSeq())
The built-in R function pretty()
works as of rockchalk 1.7.2. Any function that accepts an argument
n will work, as long as it creates a vector of values.