Re: bug in IntegerPart ?
- To: mathgroup at smc.vnet.net
- Subject: [mg47748] Re: bug in IntegerPart ?
- From: "David W. Cantrell" <DWCantrell at sigmaxi.org>
- Date: Sun, 25 Apr 2004 05:13:20 -0400 (EDT)
- References: <c6d8hl$jhl$1@smc.vnet.net>
- Sender: owner-wri-mathgroup at wolfram.com
"Dennis de Lang" <lang.NO at science.uva.nl> wrote: > Why does the following happen? > > In[1]:= (1.65 - 1.3)/0.007 > Out[1]:= 50. > In[2]:= IntegerPart[%] > Out[2]:= 49 This is not Mathematica's fault. In[3]:= FullForm[Out[1]] Out[3]//FullForm= 49.999999999999986` It is inherently perilous to use "approximate real" numbers, like 1.65, in situations like this in which discontinuous functions, such as IntegerPart, are involved. Instead, I suggest In[4]:= (165/100 - 13/10)/(7/1000) Out[4]= 50 In[5]:= IntegerPart[%] Out[5]= 50 HTH, David > but: > > In[1]:= 0.35/0.007 > Out[1]:= 50. > In[2]:= IntegerPart[%] > Out[2]:= 50 > > I'm puzzled.... > - Dennis