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Mathematica > Precision & Accuracy Control >

Accuracy

Accuracy[x]
gives the effective number of digits to the right of the decimal point in the number x.

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Accuracy[x] gives a measure of the absolute uncertainty in the value of x.

With uncertainty dx, Accuracy[x] is -Log[10, dx].

For exact numbers such as integers, Accuracy[x] is Infinity.

Accuracy[x] does not normally yield an integer result, and need not be positive.

For any approximate number x, Accuracy[x] is equal to Precision[x]-RealExponent[x].

For machine-precision numbers, Accuracy[x] gives the same as $MachinePrecision-Log[10, Abs[x]]. »

Accuracy[0.] is Log[10, $MinMachineNumber]. »

Numbers entered in the form digits``a are taken to have accuracy a.

If x is not a number, Accuracy[x] gives the minimum value of Accuracy for all the numbers that appear in x. »

Basic Examples (3)

Machine-precision number:

Arbitrary-precision number:

Exact number:

Generalizations & Extensions (1)

Applications (2)

Properties & Relations (2)

Neat Examples (1)

Precision RealExponent N Chop SetAccuracy AccuracyGoal WorkingPrecision NumberMarks

Numerical Precision

The Uncertainties of Numerical Mathematics

Numerical Evaluation & Precision

Precision & Accuracy Control

Representation of Numbers

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