Services & Resources / Wolfram Forums
-----
 /
MathGroup Archive
2006
*January
*February
*March
*April
*May
*June
*July
*August
*September
*October
*November
*December
*Archive Index
*Ask about this page
*Print this page
*Give us feedback
*Sign up for the Wolfram Insider

MathGroup Archive 2006

[Date Index] [Thread Index] [Author Index]

Search the Archive

Re: mathematica newbie question

  • To: mathgroup at smc.vnet.net
  • Subject: [mg66907] Re: [mg66879] mathematica newbie question
  • From: Sseziwa Mukasa <mukasa at jeol.com>
  • Date: Sat, 3 Jun 2006 03:25:52 -0400 (EDT)
  • Sender: owner-wri-mathgroup at wolfram.com

I forgot to include the math group and made a mistake in my earlier  
message.

> On Jun 2, 2006, at 4:09 AM, Jeremy Watts wrote:
>
>
>> Hi,
>>
>> Just trying to get to grips with Mathematica and matrices.  Why is  
>> it when I
>> enter :-
>> {0, 0, 0}, {1, -1, -1}, {-1, 1, 1}}^2
>>
>> then Mathematica returns :-
>>
>> {{0, 0, 0}, {1, 1, 1}, {1, 1, 1}}
>>
>> and not {{0,0,0},{0,0,0},{0,0,0}} (the actual square of the  
>> matrix) as I'd
>> have expected?
>>
>
> Because you did not ask for matrix multiplication, ^ operates on  
> each element of the lists individually.
>
>
>> Is it treating what I entered as separate vectors or something,  
>> and not  an
>> actual matrix?
>>
>
> Yes, in general items enclosed in {} are a list, I suggest reading  
> the Mathematica Book or the Help Browser to understand what that  
> means.  A list can be treated as a matrix when given as an argument  
> to operators that understand the concept of a matrix.  There are  
> two ways to achieve what you want:
>
> MatrixExp[{{0,0,0},{1,-1,-1},{-1,1,1}},2]

Sorry I mean MatrixPower[{{0,0,0},{1,-1,-1},{-1,1,1}},2]

>
> or
>
> With[{a={{0,0,0},{1,-1,-1},{-1,1,1}}},a.a]
>
> you can use the Help Browser to get help on these operators.

Regards,

Ssezi


  • Prev by Date: Re: Simplifying algebraic expressions
  • Next by Date: Re: calling mathematica functions from a c++ program
  • Previous by thread: Re: mathematica newbie question
  • Next by thread: Re: mathematica newbie question