Precision

Precision[x] gives the effective number of digits of precision in the number x.

Precision[x] gives a measure of the relative uncertainty in the value of x.

With absolute uncertainty dx, Precision[x] is -Log[10, dx/x].

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

Precision[x] does not normally yield an integer result.

For machine-precision numbers Precision[x] yields MachinePrecision.

Numbers entered in the form digits`p are taken to have precision p.

Numbers such as 0``a whose overall scale cannot be determined are treated as having zero precision.

Numbers with zero precision are output in StandardForm as , where is their accuracy.

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

See Section 3.1.4.

See also: Accuracy, N, Chop, SetPrecision, MachineNumberQ.

New in Version 1; modified in 5.0.

Further Examples