Re: Why Doesn't N[Pi,i] Give i Digits For Small i, Mathematica

*To*: mathgroup at smc.vnet.net*Subject*: [mg20225] Re: Why Doesn't N[Pi,i] Give i Digits For Small i, Mathematica*From*: "P.J. Hinton" <paulh at wolfram.com>*Date*: Fri, 8 Oct 1999 18:30:08 -0400*Organization*: "Wolfram Research, Inc."*References*: <innclip7tgsdm$snl@smc.vnet.net>*Sender*: owner-wri-mathgroup at wolfram.com

On 6 Oct 1999, R&M wrote: > If I execute: > > Table[{i, N[Pi, i]}, {i, 1, 20}] > > I get: > > {{1, 3.14159}, {2, 3.14159}, {3, 3.14159}, {4, 3.14159}, {5, 3.14159}, > {6, 3.14159}, {7, 3.14159}, {8, 3.14159}, {9, 3.14159}, {10, 3.14159}, > {11, 3.14159}, {12, 3.14159}, {13, 3.14159}, {14, 3.14159}, {15, > 3.14159}, {16, 3.14159}, {17, 3.1415926535897932}, > {18, 3.14159265358979324}, {19, 3.141592653589793238}, > {20, 3.1415926535897932385}} > > I'd expect something like > {{1,3},{2,3.1},{3,3.14},{4,3.141},{5,3.1416},{6,3.14159},{7,3.141593},.... > > > > It seems N[] only works as expected above 16 digits of requested > precision. > > Is my expectation wrong? What should I do to get what I want? Pay a visit to the Wolfram Research Technical Support FAQ site. You'll find an explanation there. http://support.wolfram.com/Math/Numerics/NPrintPrecision.html -- P.J. Hinton Mathematica Programming Group paulh at wolfram.com Wolfram Research, Inc. Disclaimer: Opinions expressed herein are those of the author alone.