Re: Unexpected Result for InputForm

*To*: mathgroup at smc.vnet.net*Subject*: [mg47600] Re: Unexpected Result for InputForm*From*: drbob at bigfoot.com (Bobby R. Treat)*Date*: Sat, 17 Apr 2004 02:31:40 -0400 (EDT)*References*: <c5oasf$1fd$1@smc.vnet.net>*Sender*: owner-wri-mathgroup at wolfram.com

Observe: x = 1.23456789012345678901234\ 56789`29.091514977212704*^9; doubt = 10^(-20); Log[10, doubt/x] -29.0915149772126998957108302\ 78233886544289266752931`30.61\ 646700851524 InputForm[x + doubt] 1.234567890123456789012345678\ 91`29.091514977212704*^9 InputForm[x - doubt] 1.234567890123456789012345678\ 89`29.091514977212704*^9 "Doubt" is one digit in the last place (10^-20), so relative doubt is that divided by x. Precision is the log base 10 of relative doubt. Bobby Harold.Noffke at wpafb.af.mil (Harold Noffke) wrote in message news:<c5oasf$1fd$1 at smc.vnet.net>... > $Version "5.0 for Microsoft Windows [2000] (November 18, 2003)" > > MathGroup: > > In[5]:= > $NumberMarks > Out[5]= > Automatic > In[6]:= > x=1234567890.12345678901234567890; > In[7]:= > InputForm[x] > Out[7]//InputForm= > 1.2345678901234567890123456789`29.091514977212704*^9 > > In Out[7], the `29 says there are 29 digits (correct); the *^9 says > x10**9 (correct); but the .091514977212704 in between I can't figure > out. What does this string of numbers mean, and where is it's > documentation? > > Thanks. > Harold