Loading ...
Sorry, an error occurred while loading the content.

[ai-geostats] discriminant analysis?

Expand Messages
  • MARTINEZ VARGAS Adrian
    hello mail list I have a categorical variable that describe rock type and I m interesting in quantify the relation and discriminant capacity of continuous
    Message 1 of 4 , Mar 16, 2005
    • 0 Attachment
      hello mail list

      I have a categorical variable that describe rock type and I'm
      interesting in quantify the relation and discriminant capacity of
      continuous variables (grade elements) over each category.

      The problem is that I have no normality over the domain and the classes,
      the variance and covariances are not the same, and the categories are
      not independent, that limit for example the Discriminant analysis, some
      alternative (example logistic regression )?

      a) what to use as statistical method?
      b) is possible to use discriminant analysis?

      Regards
      Adrian Martínez
    • Mahdi Osman
      Hi, Martinez, It seems to me that you are analysing coded categorical variables (eg. soft = 1, coarse = 2, hard = 3 etc.). I also assume that your coding is
      Message 2 of 4 , Mar 16, 2005
      • 0 Attachment
        Hi, Martinez,

        It seems to me that you are analysing coded categorical variables (eg. soft
        = 1, coarse = 2, hard = 3 etc.). I also assume that your coding is not
        reflecting any inherent characteristics of your rocks or your objects of
        examination.

        To be able to answer your question I would like to know the nature of your
        response variable (usually called regressand or predictand etc.). Especially
        I would like to know if it is a continuous variable or a categorical
        variable. If it is a categorical variable, how many levels do you have for
        it? Bionomial or multinomial? Ordered or nomial?

        If you have bionomial dependent variable you can use logistic regression or
        binary probit. Even though their distribution assumptions are different, the
        final conclusion will be the same. If you have ordered variable, you can use
        ologit (ordered logit) or oprobit (ordered probit). If you have multi-level
        nominal variable, you can use multinomial regression analysis.

        You can use discriminat analysis, but I would rather go for logist or probit
        methods as they are more advanced and any way will answer your quesions.

        If you need more help, pleas contact me.

        I hope this helps a little bit.

        Cheers
        Mahdi

        > hello mail list
        >
        > I have a categorical variable that describe rock type and I'm
        > interesting in quantify the relation and discriminant capacity of
        > continuous variables (grade elements) over each category.
        >
        > The problem is that I have no normality over the domain and the classes,
        > the variance and covariances are not the same, and the categories are
        > not independent, that limit for example the Discriminant analysis, some
        > alternative (example logistic regression )?
        >
        > a) what to use as statistical method?
        > b) is possible to use discriminant analysis?
        >
        > Regards
        > Adrian Martínez
        >
        >
        >
        >

        --
        -----------------------------------
        Mahdi Osman (PhD)
        E-mail: m_osm@...
        -----------------------------------

        DSL Komplett von GMX +++ Supergünstig und stressfrei einsteigen!
        AKTION "Kein Einrichtungspreis" nutzen: http://www.gmx.net/de/go/dsl
      • gpezzuchi@way.com.ar
        Hi all: Sorry to disturb with a different question, I was wondering if anyone could point out some good references on multilevel modeling within a spatial
        Message 3 of 4 , Mar 18, 2005
        • 0 Attachment
          Hi all:

          Sorry to disturb with a different question, I was wondering if anyone could
          point out some good references on multilevel modeling within a spatial
          framework, besides the work of the folks creators of Mlwin.

          Thanks in advance,

          Gaston Pezzuchi

          Mensaje citado por MARTINEZ VARGAS Adrian <martinez@...>:

          > hello mail list
          >
          > I have a categorical variable that describe rock type and I'm
          > interesting in quantify the relation and discriminant capacity of
          > continuous variables (grade elements) over each category.
          >
          > The problem is that I have no normality over the domain and the classes,
          > the variance and covariances are not the same, and the categories are
          > not independent, that limit for example the Discriminant analysis, some
          > alternative (example logistic regression )?
          >
          > a) what to use as statistical method?
          > b) is possible to use discriminant analysis?
          >
          > Regards
          > Adrian Martínez
          >
          >
          >
          >




          -------------------------------------------------
          Internet Way - Webmail - http://www.way.com.ar
        Your message has been successfully submitted and would be delivered to recipients shortly.