Re: Machine-precision Exp function
- To: mathgroup at smc.vnet.net
- Subject: [mg93624] Re: Machine-precision Exp function
- From: Roman <rschmied at gmail.com>
- Date: Tue, 18 Nov 2008 07:22:20 -0500 (EST)
- References: <email@example.com>
Daniel Lichtblau kindly pointed out a very simple solution: with SetSystemOptions["CatchMachineUnderflow" -> False] the default behavior of switching to arbitrary-precision numbers can be suppressed. After the above command, we get In := Exp[-1`*^6] Out = 0.` and the execution speed is identical to that of the compiled command. There are some hints in this direction in the help file under $MinMachineNumber, but they seem outdated (Version 18.104.22.168) as they invoke the command Developer`SetSystemOption["CatchMachineUnderflow" -> False] which no longer exists. Roman.