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From |
Nina YIN <yinnina.ccer@gmail.com> |

To |
statalist@hsphsun2.harvard.edu |

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 <njcoxstata@gmail.com> 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 <yinnina.ccer@gmail.com> 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? > * > * For searches and help try: > * http://www.stata.com/help.cgi?search > * http://www.stata.com/support/statalist/faq > * http://www.ats.ucla.edu/stat/stata/ -- * * For searches and help try: * http://www.stata.com/help.cgi?search * http://www.stata.com/support/statalist/faq * http://www.ats.ucla.edu/stat/stata/

**Follow-Ups**:**Re: st: how to define a matrix with mathematical expression***From:*Nick Cox <njcoxstata@gmail.com>

**References**:**st: how to define a matrix with mathematical expression***From:*Nina YIN <yinnina.ccer@gmail.com>

**Re: st: how to define a matrix with mathematical expression***From:*Nick Cox <njcoxstata@gmail.com>

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