Precision (computer science)
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In computer science, precision of a numerical quantity is a measure of the detail in which the quantity is expressed. This is usually measured in bits, but sometimes in decimal digits. It is related to precision in mathematics, which describes the number of digits that are used to express a value.
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|+Precision of java data types
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! width="10%" style="background:#efefef;" | Type name
! width="10%" style="background:#ffdead;" | Precision (binary bits)
| width="40%" style="background:#efefef;" | Range
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| byte
| 8
| -128 to +127
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| short
| 16
| -32,768 to 32,767
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| int
| 32
| -2,147,483,648 to 2,147,483,647
|-
| long
| 64
| -9,223,372,036,854,775,808 to 9,223,372,036,854,775,807
|}
Rounding error
Precision is often the source of rounding errors in computation. The number of bits used to store a number will often cause some loss of accuracy. An example would be to store sin(0.1) in IEEE single precision floating point standard. The error is then often magnified as subsequent computations are made to the data (it can also be reduced).
See also
- Arbitrary-precision arithmetic
- Precision (arithmetic)
- IEEE754 (IEEE floating point standard)