RealDigits

RealDigits[x] gives a list of the digits in the approximate real number x, together with the number of digits that are to the left of the decimal point.

RealDigits[x, b] gives a list of base-b digits in x.

RealDigits[x, b, len] gives a list of len digits.

RealDigits[x, b, len, n] gives len digits starting with the coefficient of .

RealDigits[x] normally returns a list of digits whose length is equal to Precision[x].

RealDigits[x] and RealDigits[x, b] normally require that x be an approximate real number, returned for example by N. RealDigits[x, b, len] also works on exact numbers.

For integers and rational numbers with terminating digit expansions, RealDigits[x] returns an ordinary list of digits. For rational numbers with non-terminating digit expansions it yields a list of the form , , ... , , , ... representing the digit sequence consisting of the followed by infinite cyclic repetitions of the .

If len is larger than Log[10, b] Precision[x], then remaining digits are filled in as Indeterminate.

RealDigits[x, b, len, n] starts with the digit which is the coefficient of , truncating or padding with zeros as necessary.

RealDigits[x, b, len, -1] starts with the digit immediately to the right of the base-b decimal point in x.

The base b in RealDigits[x, b] need not be an integer. For any real b such that , RealDigits[x, b] successively finds the largest integer multiples of powers of b that can be removed while leaving a non-negative remainder.

RealDigits[x] discards the sign of x.

FromDigits can be used as the inverse of RealDigits.

See Section 3.1.3.

Implementation Notes: see Section A.9.4.

See also: MantissaExponent, IntegerDigits, BaseForm, FromDigits, ContinuedFraction, MultiplicativeOrder.

New in Version 2; modified in 4.

Further Examples