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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 14:55:05 +0200 |

Okay, Nick, thank you for your answer, Symbolic manipulation is exactly what I want. Maybe I should return to Matlab to deal with it. On Mon, Sep 10, 2012 at 2:49 PM, Nick Cox <njcoxstata@gmail.com> wrote: > I don't think I can add much to my previous post. The key is that > Stata expects to be given a number for each element of a matrix. It > won't do symbolic manipulation, if that is what you are seeking. > > If you made concrete what your matrix is, that might help make clear > what you are finding difficult to understand. > > Nick > > On Mon, Sep 10, 2012 at 1:37 PM, Nina YIN <yinnina.ccer@gmail.com> wrote: >> 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/ -- Best Regards, Nina YIN Toulouse School of Economics Manufacture des Tabacs 21 Allee de Brienne Toulouse, 31000, France Tel: 0033-(0)5 6123 8348 * * 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:*Maarten Buis <maartenlbuis@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>

**Re: 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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