RE : 34.123*89 = 3036.95 (3036.947)
- To: mathgroup at smc.vnet.net
- Subject: [mg47923] RE : [mg47905] 34.123*89 = 3036.95 (3036.947)
- From: "Florian Jaccard" <florian.jaccard at eiaj.ch>
- Date: Fri, 30 Apr 2004 19:27:02 -0400 (EDT)
- Sender: owner-wri-mathgroup at wolfram.com
Hello Thomas, This question has just been discussed this month. See the related link : http://forums.wolfram.com/mathgroup/search/index.cgi?q=Bug+in+IntegerPart To make it short : Cumputers represent the floating point numbers with a finite precision, in base 2. So the result of a computation cannot have infinite precision. With Mathematica, the default precision is $MachinePrecision , i.e. less then 16 significant digits. If you look at the representation with 7 significant digits, you may be happier : In[22]:= NumberForm[34.123*89, 7] Out[22]//NumberForm= 3036.947 Speziell mit Mathematica: You may also want to precise that your first number has , let us say, 50 significant digits. In this case, the result will also have 50 significant digits : In[23]:= 34.123`50*89 Out[23]= 3036.9470000000000000000000000000000000000000000000 Beste Grüsse F.Jaccard -----Message d'origine----- De : Thomas Schulz [mailto:thomas-k-schulz at t-online.de] Envoyé : vendredi, 30. avril 2004 01:40 À : mathgroup at smc.vnet.net Objet : [mg47905] 34.123*89 = 3036.95 (3036.947) I am a NewBe - and i dont understand the Result. Mathematica says that 34.123*89 = 3036.94699999997 but its 3036.947... How can i change this? i use a IBook (G4) with Mac OS X. THX Thomas