How to ensure ( Overflow[] -> Indeterminate )
- To: mathgroup at smc.vnet.net
- Subject: [mg114705] How to ensure ( Overflow[] -> Indeterminate )
- From: "Ted Ersek" <ersekt at md.metrocast.net>
- Date: Mon, 13 Dec 2010 03:54:41 -0500 (EST)
Recall the thread: "Are these bugs fixed in Mathematica 8 ?" found at http://forums.wolfram.com/mathgroup/archive/2010/Dec/msg00260.html There we discussed cases where some (many?) functions in Mathematica 8 treat any Overflow as a positive real number. Fortunately one rarely gets an overflow in Mathematica because $MaxNumber is a very large value. However, if you ever do get an Overflow you can't have faith in any computation that makes use of your Overflow[]. Until Mathematica can work with an overflow reliably we are better of using the following. In[1]:= Off[General::ovfl]; Unprotect[Overflow]; Overflow[]=Indeterminate; ------------------------------------- Well at first that seems to work for me using $Version = "7.0 for Microsoft Windows (32-bit) (January 30, 2009)." In[4]:= 0 < 3-Overflow[] Out[4]= 0 < Indeterminate In[5]:= Element[ 3-Overflow[],Reals ] Out[5]= Element[ Indeterminate, Reals ] Bu wait it only works in simple cases. Consider the next two examples. In[6]:= 0<3-4*$MaxNumber Out[6]= True In[7]:= Element[($MaxNumber (-0.664-0.747 I))^4,Reals] Out[7]= True ---------------------------------- Does anyone know how we can ensure an Overflow[] is always converted to Indeterminate? -- Ted Ersek --