foldchange: Compute fold-change or convert between log-ratio and...

View source: R/foldchange.R

foldchangeR Documentation

Compute fold-change or convert between log-ratio and fold-change.

Description

foldchange computes the fold change for two sets of values. logratio2foldchange converts values from log-ratios to fold changes. foldchange2logratio does the reverse.

Usage

foldchange(num, denom)

logratio2foldchange(logratio, base = 2)

foldchange2logratio(foldchange, base = 2)

Arguments

num, denom

vector/matrix of numeric values

logratio

vector/matrix of log-ratio values

base

Exponential base for the log-ratio.

foldchange

vector/matrix of fold-change values

Details

Fold changes are commonly used in the biological sciences as a mechanism for comparing the relative size of two measurements. They are computed as: num/denom if num>denom, and as -denom/num otherwise.

Fold-changes have the advantage of ease of interpretation and symmetry about num=denom, but suffer from a discontinuity between -1 and 1, which can cause significant problems when performing data analysis. Consequently statisticians prefer to use log-ratios.

Value

A vector or matrix of the same dimensions as the input containing the converted values.

Functions

  • foldchange: Compute fold-change.

  • logratio2foldchange: Compute foldchange from log-ratio values.

  • foldchange2logratio: Compute log-ratio from fold-change values.

Author(s)

Gregory R. Warnes greg@warnes.net

Examples



a <- 1:21
b <- 21:1

f <- foldchange(a, b)

cbind(a, b, f)

gtools documentation built on July 12, 2022, 1:06 a.m.