| matchNone {tuple} | R Documentation |
Return a Symbol That Matches No Values
Description
The tag value is chosen from among special characters so that it does not appear anywhere in the reference input data. The shortest possible tag is chosen.
Usage
matchNone(x, table = list(c(".", "!", "/"), c("NA", "na")))
Arguments
x |
A vector or matrix. |
table |
The lookup table against which to seek non-matches. This can be a simple vector, or it can be a list of two vectors. |
Details
This function is used in other packages by the same author to extend missing data handling in R. It provides for flexible missing data identifiers where needed by an S4 class, and similar unmatched identifiers for other dirty data problems.
Value
A string composed of the strings in the table.
The default list choses the first non-matching value
out of 179 values that are unlikely to be used in
most real sets of data.
If only table is specified, the possible
values for a non-matching string, ordered from the
most to the least preferable, are returned.
Examples
my.x <- c(1,2,3,2,3,1,2)
matchNone(my.x)
matchNone(c(my.x,"."))
matchNone(c(my.x,".","!"))
matchNone(c(my.x,".","!","/"))
matchNone(c(my.x,".","!","/",".."))
matchNone(table = ".")