references_best: Best references

In atime: Asymptotic Timing

Best references

Description

Compute best asymptotic references.

Usage

references_best(L, unit.col.vec=NULL, more.units=NULL, fun.list=NULL)

Arguments

L	List output from atime.
unit.col.vec	Named character vector of units, default NULL means standard units (kilobytes and seconds).
more.units	Named character vector of units to add to unit.col.vec, default NULL means nothing.
fun.list	List of asymptotic complexity reference functions, default NULL means to use package default.

Value

list of class "references_best" with elements references (data table of references), measurements (data table of measurements).

Author(s)

Toby Dylan Hocking

Examples

## Example 1: polynomial and exponential time string functions.
string.result <- atime::atime(
  N=unique(as.integer(10^seq(0,3.5,l=100))),
  setup={
    subject <- paste(rep("a", N), collapse="")
    pattern <- paste(rep(c("a?", "a"), each=N), collapse="")
  },
  seconds.limit=0.001,
  PCRE.match=regexpr(pattern, subject, perl=TRUE),
  TRE.match=regexpr(pattern, subject, perl=FALSE),
  constant.replacement=gsub("a","constant size replacement",subject),
  linear.replacement=gsub("a",subject,subject))
(string.best <- atime::references_best(string.result))
## plot method shows each expr in a separate panel.
plot(string.best)

## Example 2: split data table vs frame, constant factor difference.
library(data.table)
split.result <- atime::atime(
  N=as.integer(10^seq(1, 7)),
  setup={
    set.seed(1)
    DT <- data.table(
      x1 = rep(c("c","d"), l=N),
      x2 = rep(c("x","y"), l=N),
      x3 = rep(c("a","b"), l=N),
      y = rnorm(N)
    )[sample(.N)]
    DF <- as.data.frame(DT)
  },
  seconds.limit=0.001,
  frame=split(DF[names(DF) != "x1"], DF["x1"], drop = TRUE),
  table=split(DT, by = "x1", keep.by = FALSE, drop = TRUE)
)
split.best <- atime::references_best(split.result)
plot(split.best)

atime documentation built on April 3, 2023, 5:30 p.m.