Learn R Programming

SLmetrics (version 0.3-4)

preorder.matrix: Preorder Matrices

Description

A generic S3 function for somehting long. This function dispatches to S3 methods in preorder() and performs no input validation. If you supply NA values or vectors of unequal length (e.g. length(x) != length(y)), the underlying C++ code may trigger undefined behavior and crash your R session.

Defensive measures

Because preorder() operates on raw pointers, pointer-level faults (e.g. from NA or mismatched length) occur before any R-level error handling. Wrapping calls in try() or tryCatch() will not prevent R-session crashes.

To guard against this, wrap preorder() in a “safe” validator that checks for NA values and matching length, for example:

safe_preorder <- function(x, y, ...) {
  stopifnot(
    !anyNA(x), !anyNA(y),
    length(x) == length(y)
  )
  preorder(x, y, ...)
}

Usage

# S3 method for matrix
preorder(x, decreasing = FALSE, ...)

Value

A <matrix> of same dimensions as the input <matrix>

Arguments

x

A <matrix> to be sorted

decreasing

A <logical>

...

Arguments passed into other methods

See Also

Other Utilities: presort()