Re: Converting an expression to a list of terms?
- To: mathgroup at smc.vnet.net
- Subject: [mg71619] Re: Converting an expression to a list of terms?
- From: "dimitris" <dimmechan at yahoo.com>
- Date: Sat, 25 Nov 2006 05:36:58 -0500 (EST)
- References: <200611200743.CAA09240@smc.vnet.net><ejtdhl$j0v$1@smc.vnet.net>
It's not a good programming practise to treat independently each
element of one expression.
Treat the expession as a whole.
lst=a+b-c+d-e;
List@@lst
{a,b,-c,d,-e}
lst/.x_+y___\[RuleDelayed]{x,y}
{a,b,-c,d,-e}
I highly recomend you reading Chapter 2 of the Mathematica Book.
FrontEndExecute[{HelpBrowserLookup["MainBook", "2"]}]
Regards
Dimitris
János wrote:
> On Nov 20, 2006, at 2:43 AM, AES wrote:
>
> > How to convert an expression consisting of a sum of terms in an Output
> > cell:
> >
> > A + B - C + . . .
> >
> > (where A, B, C are themselves product expressions) to a list
> >
> > {A, B, -C, . . . }
> >
> > in some easier fashion than doing it by hand using Find and Replace?
>
> My newbie approach would be:
>
> In[1]:=
> expr = a + b - c + d - e;
>
> In[2]:=
> Table[expr[[i]],
> {i, 1, Length[expr]}]
> Out[2]=
> {a, b, -c, d, -e}
>
> János
>
>
> ----------------------------------------------
> Trying to argue with a politician is like lifting up the head of a
> corpse.
> (S. Lem: His Master Voice)
- References:
- Converting an expression to a list of terms?
- From: AES <siegman@stanford.edu>
- Converting an expression to a list of terms?