Re: [TS 28872]--Re:Pattern::nodef: No default setting found for Piecewise in position 2 when length is 2.
- To: mathgroup at smc.vnet.net
- Subject: [mg81833] Re: [TS 28872]--Re:Pattern::nodef: No default setting found for Piecewise in position 2 when length is 2.
- From: "Chris Chiasson" <chris at chiasson.name>
- Date: Thu, 4 Oct 2007 04:30:27 -0400 (EDT)
- References: <200710021730.l92HU1Fq025167@localhost.localdomain>
It would come up when people are constructing other expressions from Piecewise objects or when people are constructing Piecewise objects from other expressions, especially in any environment where there are OwnValues or DownValues that must be prevented from executing (which may or may not occur as part of a pattern or condition test). I found it when I was writing my second response in this thread, though I constructed my solution without it: http://groups.google.com/group/comp.soft-sys.math.mathematica/browse_thread/thread/96490ac6a4d5bf3d/ Lastly, the present behavior doesn't fit in with the rest of the Mathematica framework. On Tue, 2 Oct 2007 17:30:01 UT, mathgroup <mathgroup at smc.vnet.net> wrote: > -- Wolfram Research Technical Support -- > > This is a response to your email. > The reply to your question can be found at the bottom of this message. > Our classification number for this message is: [TS 28872] > Please give this number in any future correspondence > related to this question. If you leave this number in > the Subject: header in the form [TS 28872], it will > automatically be reassigned to the original technician. > > From: "Chris Chiasson" <chris at chiasson.name> > Date: Wed, 19 Sep 2007 10:01:13 -0500 > Subject: Pattern::nodef: No default setting found for Piecewise in position 2 when length is 2. > To: mathgroup <mathgroup at smc.vnet.net>,"Wolfram Research Support" <support at wolfram.com> > > Is there a good reason why this shouldn't be fixed? > > -- > http://chris.chiasson.name/ > > > _________________________________________________________________________ > ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ > > Chris, > > I looked at the example you posted to mathgroup: > > Hold[Piecewise[{{x,blah}}]]/.HoldPattern[Piecewise] > [conditions_,default_.]:>f[whatever]+default > > It is not clear to me when this would come up. If you have a "this is > a problem because ... or this is a problem when ..." I will add that to > the report. > > Tom Zeller > Wolfram Research Technical Support > > > ---------------------------------------------------------------------------- > > If this issue is resolved, please consider taking a few minutes > to give us some feedback on your experience. Please visit > http://support.wolfram.com/survey/?trackingnumber=28872 > and give your honest answers to these three short questions. > Thanks for taking the time to help us improve. > -- http://chris.chiasson.name/