Re: Null's not null?

*To*: mathgroup at smc.vnet.net*Subject*: [mg69416] Re: Null's not null?*From*: "Jean-Marc Gulliet" <jeanmarc.gulliet at gmail.com>*Date*: Mon, 11 Sep 2006 05:39:21 -0400 (EDT)*References*: <ee0t74$b5m$1@smc.vnet.net> <45040422.2000205@gmail.com> <p06230903c12a4b792c82@171.66.188.107>

On 9/11/06, AES <siegman at stanford.edu> wrote: > >What about using the \[Null] character [1], character that is not displayed? > > > >Table[If[Random[] < 0.5, 1, \[Null]], {10}] > > > >HTH, > >Jean-Marc > > > >[1] _The Mathematica Book_, Section 3.10.5 "Structural Elements and > >Keyboard Characters" > >http://documents.wolfram.com/mathematica/book/section-3.10.5 > > > Thanks -- works great. (Except: How can I edit it, if I can't see it > in the Input cell?!?) Pertinent question, indeed! I think the best way to edit such invisible characters, \[Null] and alike, is to select the cell you want to modify and use the sequence of keys Shift+Ctrl+ E (under Windows) -- this will display the cell in a cell expression form --, do the changes you want, then return to a normal form with the same sequence of keys. In[2]:= Cell["\<\ Table[If[Random[] < 0.5, 1, \[Null]], {10}]\ \>", \ "Input", CellLabel->"In[2]:="] Out[2]= Cell["{\[Null], \[Null], \[Null], 1, \[Null], 1, 1, \[Null], \ 1, \[Null]}", "Output", CellLabel->"Out[2]="] Regards, Jean-Marc