Re: Re: Converting an expression to a list of terms?
- To: mathgroup at smc.vnet.net
- Subject: [mg71743] Re: [mg71555] Re: Converting an expression to a list of terms?
- From: János <janos.lobb at yale.edu>
- Date: Tue, 28 Nov 2006 06:03:56 -0500 (EST)
- References: <200611200743.CAA09240@smc.vnet.net><ejtdhl$j0v$1@smc.vnet.net> <200611231041.FAA25205@smc.vnet.net>
Dimitris,
I had my disclaimer: "newbie approach" as a red flag. That is a
clear indication that it is by the grace of god that I am able to
present a solution and that solution is good just for me. Good
programming technique should come from member emeritizeuses of this
group. I am just an accidental stalker here nothing more.
I read Chapter 2 from the Book. As a matter of fact I read it
multiple times. I have to confess that even if I would have the time
to read it ab infinity, I still would not get more out of it than I
have as it is. Steven just did not sex it up to get me more exited
about it :)
With the best,
János
On Nov 23, 2006, at 5:41 AM, dimitris wrote:
> 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)
----------------------------------------------
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>
- Re: Converting an expression to a list of terms?
- From: "dimitris" <dimmechan@yahoo.com>
- Converting an expression to a list of terms?