Re: Annoying Little Problem

*To*: mathgroup at smc.vnet.net*Subject*: [mg24739] Re: [mg24701] Annoying Little Problem*From*: BobHanlon at aol.com*Date*: Wed, 9 Aug 2000 02:31:42 -0400 (EDT)*Sender*: owner-wri-mathgroup at wolfram.com

In a message dated 8/4/2000 1:30:31 AM, ayrton at rac1.wam.umd.edu writes: >I'm having an annoying little problem with version 4.0.1.0. I wrote the > >following info in a notebook and ran it: > >Clear[v2] >v2 = {4, 0, -6} >N[Sqrt[v2.v2]] >N[Sqrt[v2.v2], 3] > >Now the third line gives me 7.2111 but the fourth line gives me the >same instead of 7.21. Does anyone have any idea what may be the problem? > >Am I doing something wrong? > ?N "N[expr] gives the numerical value of expr. N[expr, n] attempts to give a \ result with n-digit precision." Note that while this indicates the precision of the result, it does not say anything about how the result is printed. Clear[v2]; v2 = {4, 0, -6}; Table[NumberForm[N[Sqrt[v2.v2]], k], {k, 7}] {"7.", "7.2", "7.21", "7.211", "7.2111", "7.2111", "7.211103"} Note that for k=5 and k=6 the display is the same, i.e., the trailing zero is suppressed for k=6. To display the trailing zero Table[NumberForm[N[Sqrt[v2.v2]], {k, k - 1}, NumberPadding -> {"", "0"}], {k, 7}] {"7.", "7.2", "7.21", "7.211", "7.2111", "7.21110", "7.211103"} Bob Hanlon