Editing Dyadic rational (section)

===In computing===
Dyadic rationals are central to [[computer science]] as a type of fractional number that many computers can manipulate directly.{{r|reswel}} In particular, as a data type used by computers, [[Floating-point arithmetic|floating-point numbers]] are often defined as integers multiplied by positive or negative powers of two. The numbers that can be represented precisely in a floating-point format, such as the [[IEEE floating point|IEEE floating-point datatypes]], are called its representable numbers. For most floating-point representations, the representable numbers are a subset of the dyadic rationals.{{r|kirk-hwu}} The same is true for [[fixed-point arithmetic|fixed-point datatypes]], which also use powers of two implicitly in the majority of cases.{{r|kneusel}} Because of the simplicity of computing with dyadic rationals, they are also used for exact real computing using [[interval arithmetic]],{{r|vdh}} and are central to some theoretical models of [[computable number]]s.{{r|ko|zr|asz}}

Generating a [[random variable]] from random bits, in a fixed amount of time, is possible only when the variable has finitely many outcomes whose probabilities are all dyadic rational numbers. For random variables whose probabilities are not dyadic, it is necessary either to approximate their probabilities by dyadic rationals, or to use a random generation process whose time is itself random and unbounded.{{r|jvv}}