yields a version of expr in which all numbers have been set to have accuracy a.


  • When SetAccuracy is used to increase the accuracy of a number, the number is padded with zeros. The zeros are taken to be in base 2. In base 10, the additional digits are usually not zeros.
  • SetAccuracy returns an arbitraryprecision number even if the number of significant digits obtained will be less than $MachinePrecision.
  • When expr contains machineprecision numbers, SetAccuracy[expr,a] can give results that differ from one computer system to another.
  • SetAccuracy will first expose any hidden extra digits in the internal binary representation of a number, and, only after these are exhausted, add trailing zeros. »
  • 0.004``25 generates a number with all trailing digits zero and accuracy 25 on any computer system.
  • SetAccuracy[expr,a] does not modify expr itself.

ExamplesExamplesopen allclose all

Basic Examples  (2)Basic Examples  (2)

Set the accuracy of all numbers in an expression to 20:

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Convert from a machine number to an arbitrary-precision number with accuracy 32:

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Introduced in 1991