gives the effective number of digits to the right of the decimal point in the number x.
- 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. »
Examplesopen allclose all
Introduced in 1988
(1.0)| Updated in 2003