RE: Severe ToExpression Fault?
- To: mathgroup at smc.vnet.net
- Subject: [mg42903] RE: [mg42892] Severe ToExpression Fault?
- From: "Wolf, Hartmut" <Hartmut.Wolf at t-systems.com>
- Date: Sat, 2 Aug 2003 04:12:27 -0400 (EDT)
- Sender: owner-wri-mathgroup at wolfram.com
>-----Original Message----- >From: nils at theune.com [mailto:nils at theune.com] To: mathgroup at smc.vnet.net >Sent: Friday, August 01, 2003 7:26 AM >To: mathgroup at smc.vnet.net >Subject: [mg42903] [mg42892] Severe ToExpression Fault? > > >Hi folks, > >running Mathematica 4.0.1 I am stuck with the following problem: > >Input: >Print["-1,97E-04"]; >Print[StringReplace["-1,97E-04", {"," -> "."}]]; >Print[ToExpression[StringReplace["-1,97E-04", {"," -> "."}]]]; > >Output: >-1,97E-04 >-1.97E-04 >-9.35502 > >Can somebody explain this to me? Why does the ToExpression Function >not make the decimal -1.97E-04 out of the String "-1.97E-04". What in >the hell is going wrong (-9.35502->"Where does this number come >from?") and what can be done to circumvent the ToExpression function. > >I am greatful for any kind of comments on this problem/bug. > >regards >Nils > No severe fault, a simple misunderstanding, compare: In[1]:= -1.97E-04 Out[1]= -9.35502 In[2]:= -1.97 * E - 4 Out[2]= -9.35502 In[3]:= -1.97*^-4 Out[3]= -0.000197 but Mathematica may understand the format you chose, if you specify the right conversion: In[5]:= Read[StringToStream["-1.97E-04"], Real] Out[5]= -0.000197 -- Hartmut Wolf