Re: Is there a simple way to transform 1.1 to 11/10?

*To*: mathgroup at smc.vnet.net*Subject*: [mg92979] Re: Is there a simple way to transform 1.1 to 11/10?*From*: dh <dh at metrohm.ch>*Date*: Wed, 22 Oct 2008 05:36:18 -0400 (EDT)*References*: <gdkajv$4r2$1@smc.vnet.net>

Hi Alain, Rationalize[x,0] does not give a rational approx. without errors as the "0" may imply. Instead it gives an approximation with the precision of x. Even Rationalize[x,dx] does at most give an approximation with a precision of x (even if dx is smaller). hope this helps, Daniel Alain Cochard wrote: > The obvious > > In[1]:= x=1.1`Infinity > > is not syntactically correct. > > I understand that SetPrecision[1.1,Infinity] does not work either: > > In[3]:= SetPrecision[1.1,Infinity] > > 2476979795053773 > Out[3]= ---------------- > 2251799813685248 > > In[4]:= N[%,20] > > Out[4]= 1.1000000000000000888 > > I searched the newsgroup and thought I had the solution with Rationalize: > > In[5]:= Rationalize[1.1,0] > > 11 > Out[5]= -- > 10 > > But > > In[9]:= Rationalize[1.000000001,0] > > 999999918 > Out[9]= --------- > 999999917 > > In[10]:= N[%,20] > > Out[10]= 1.0000000010000000830 > > So any simple way? > > Thanks, > Alain > -- Daniel Huber Metrohm Ltd. Oberdorfstr. 68 CH-9100 Herisau Tel. +41 71 353 8585, Fax +41 71 353 8907 E-Mail:<mailto:dh at metrohm.com> Internet:<http://www.metrohm.com>