BUILT-IN MATHEMATICA SYMBOL

# SetPrecision

SetPrecision[expr, p]
yields a version of expr in which all numbers have been set to have precision p.

## DetailsDetails

• When SetPrecision is used to increase the precision 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.
• SetPrecision returns an arbitrary-precision number, even if the precision requested is less than \$MachinePrecision.
• SetPrecision[expr, MachinePrecision] converts numbers in expr to machine precision.
• If there are numbers too large or small to represent machine-precision numbers, SetPrecision[expr, MachinePrecision] will convert them to arbitrary-precision numbers with precision \$MachinePrecision.
• If expr contains machine-precision numbers, SetPrecision[expr, p] can give results that differ from one computer system to another.
• SetPrecision will first expose any hidden extra digits in the internal binary representation of a number, and, only after these are exhausted, add trailing zeros. »
• generates a number with all trailing digits zero and precision 25 on any computer system.
• SetPrecision[expr, p] does not modify expr itself.

## ExamplesExamplesopen allclose all

### Basic Examples (3)Basic Examples (3)

Convert all numbers in an expression to 20-digit precision:

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Convert all numbers to machine precision:

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Convert from a machine number to an arbitrary-precision number:

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