RE: BracketingBar for output
- To: mathgroup at smc.vnet.net
- Subject: [mg15768] RE: [mg15717] BracketingBar for output
- From: "Ersek, Ted R" <ErsekTR at navair.navy.mil>
- Date: Sun, 7 Feb 1999 02:03:49 -0500 (EST)
- Sender: owner-wri-mathgroup at wolfram.com
Peter Breitfeld wrote:
_______________
In my "personal package" I have the function Betrag[x_]:=Sqrt[x.x]
Now I want that in cases where this function can't be evaluated, the
output in StandardForm is displays as |x|. (left and right
BracketingBar, these symbols you get when entering `ESC l| ESC' and
`ESC r| ESC'.
To make it more clear (I hope :-)) I want the following behavior
In[1] Betrag[foo]
Out[1] |foo|
but
In[1] Betrag[{2,2,1}]
Out[1] 3
_________________________
This should do it.
(***** Code Begins *******)
Betrag[x_List]:=Sqrt[x.x];
MakeBoxes[Betrag[expr_],StandardForm]:=
RowBox[{"\[LeftBracketingBar]",
MakeBoxes[expr,StandardForm],"\[RightBracketingBar]"
}]
(****** Code Ends *******)
Regards,
Ted Ersek