Truncation

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In mathematics and computer science, truncation is limiting the number of digits right of the decimal point.

Truncation and floor function[edit]

Truncation of positive real numbers can be done using the floor function. Given a number to be truncated and , the number of elements to be kept behind the decimal point, the truncated value of x is

However, for negative numbers truncation does not round in the same direction as the floor function: truncation always rounds toward zero, the floor function rounds towards negative infinity. For a given number , the function ceil is used instead

.

In some cases trunc(x,0) is written as [x].[citation needed] See Notation of floor and ceiling functions.

Causes of truncation[edit]

With computers, truncation can occur when a decimal number is typecast as an integer; it is truncated to zero decimal digits because integers cannot store non-integer real numbers.

In algebra[edit]

An analogue of truncation can be applied to polynomials. In this case, the truncation of a polynomial P to degree n can be defined as the sum of all terms of P of degree n or less. Polynomial truncations arise in the study of Taylor polynomials, for example.[1]

See also[edit]

References[edit]

  1. ^ Spivak, Michael (2008). Calculus (4th ed.). p. 434. ISBN 978-0-914098-91-1.

External links[edit]