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Re: st: how to define a matrix with mathematical expression
From
Nina YIN <[email protected]>
To
[email protected]
Subject
Re: st: how to define a matrix with mathematical expression
Date
Mon, 10 Sep 2012 14:37:39 +0200
Hi Nick,
Thank you for your reply!
Does you mean that I should make these derivations into vectors and
then define them into matrix?
However, it's a big matrix with size110*110. Also I want to define the
element "x_{ij}" as
if some condition satisfied, x_{ij}= partial Di/partial Pj;
else x_{ij}=0.
Therefore, it would be a problem if it need me to define each element by hand.
Do you have any idea about this? Thank you very much!
Best,
Nina
On Mon, Sep 10, 2012 at 2:27 PM, Nick Cox <[email protected]> wrote:
> I think you are correct. If your matrix is a matrix of partial
> derivatives, you have to do any calculus derivations yourself.
>
> Nick
>
> On Mon, Sep 10, 2012 at 1:22 PM, Nina YIN <[email protected]> wrote:
>
>> I am trying to construct a matrix with elements defined in
>> mathematical expression. For example, a m*m matrix A with elements
>> "a_{ij}"=partial Di/ partial Pj. Di (Pj) is the i-th ( j-th ) element
>> of variable D(P).
>>
>> I just know -matrix define and -mkmat, however I didn't find out that
>> these two commands could help me in this problem. Do I understand it
>> well?
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