Re: String-to-Number Conversion Precision

*To*: mathgroup at smc.vnet.net*Subject*: [mg112355] Re: String-to-Number Conversion Precision*From*: Albert Retey <awnl at gmx-topmail.de>*Date*: Fri, 10 Sep 2010 05:11:05 -0400 (EDT)*References*: <i6crfo$sa1$1@smc.vnet.net>

Am 10.09.2010 10:50, schrieb Ben: > I'm reading real numbers from a file and I'm trying to convert them > from string format (with arbitrary precision) to real values with the > same precision as given in the strings. > > For example, when I convert "1.867524468", I want the result to be set > to precision 10. Instead, I get the following. > > In[1]:= string = "1.867524468" > Out[1]:= "1.867524468" > > In[2]:= x = ToExpression[string] > Out[2]:= 1.86752 > > The last 4-digits get cut off. This is fine for when I do math with > the number because the extra digits are still stored, but not when I > want to rewrite the number to a different file. When I convert the > number back to a string for file output, the last 4-digits remain > lost. > > In[3]:= ToString[x] > Out[3]:= "1.86752" > > Is there a function or formula I can use to automatically set the > precision of these numbers to their precision in the string? Thanks. > ToString[NumberForm[x, 10]] hth, albert