Re: Appending an element to a list
- To: mathgroup at smc.vnet.net
- Subject: [mg23921] Re: Appending an element to a list
- From: Brian Higgins <bghiggins at ucdavis.edu>
- Date: Fri, 16 Jun 2000 00:57:01 -0400 (EDT)
- References: <WIl15.112$lD2.68356@ralph.vnet.net> <8i9os0$2d4@smc.vnet.net>
- Sender: owner-wri-mathgroup at wolfram.com
Felix, Perhaps this will do what you need: myAppendFunc[oldList_, newList_ /; Length[newList] > 0] := Append[oldList, newList] myAppendFunc[oldList_, newList_ /; Length[newList] == 0] := oldList And here is a test: c1 = {{2, 2}, {3, 3}} myAppendFunc[c1, {2, 5}] {{2, 2}, {3, 3}, {2, 5}} myAppendFunc[c1, {}] {{2, 2}, {3, 3}} Cheers, Brian In article <8i9os0$2d4 at smc.vnet.net>, Felix Farkas <farkas at icamail.epfl.ch> wrote: > Hello, > i do have a problem, which is probably very easy, but i couldn't find > a reasonable way to solve it. I would appreciate very much any hint. > > I have a list of lists. My purpose is to append a new elements to this > list. These elements are generated by some function. Sometimes the > output of the function is an empty list meaning no element. In this > situation Append includes the new element in the list. i would like to > avoid this behaviour. > > ex: > > In[1]:= d={} > Out[1]= {} > > In[2]:= Append[{{2,2},{3,3}},d] > Out[2]:= {{2,2},{3,3},{}} > > Thanks in advance. Felix Farkas > > Sent via Deja.com http://www.deja.com/ Before you buy.