Bookmark and Share

Notice: On March 31, it was announced that Statalist is moving from an email list to a forum. The old list will shut down on April 23, and its replacement, statalist.org is already up and running.


[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Fwd: st: RE thread: SEM with categorical variables


From   Laura Maria Schwirz <schwirzl@tcd.ie>
To   statalist@hsphsun2.harvard.edu
Subject   Fwd: st: RE thread: SEM with categorical variables
Date   Wed, 13 Mar 2013 15:06:08 +0000

Thanks for quick reply. It actually works up to a certain point..
local thevars hewsonstrong hewsonknowo hewsonint hewsoninspi
hewsonmoral hewsoncom hewsondecent hewsondepend hewsonrel hewsonsens

. polychoric `thevars'

Polychoric correlation matrix

(output omitted)

. mat polychR = r(R)

.  forvalues i=1/`: word count `thevars' ' {
  2.  forvalues j=1/`i' {
  3.  local setcor `setcor' `=polychR[`i',`j']'
  4.  }
  5.  if `i' < `: word count `thevars' ' local setcor `setcor' \
  6.  }

.  local N = _N

.
end of do-file

. do "/var/folders/lw/lweDBBEGH68nFpOhV2D+gk+++TI/-Tmp-//SD00459.000000"

.  clear

.  ssd init hewsonstrong hewsonknowo hewsonint hewsoninspi hewsonmoral
hewsoncom hewsondecent hewsonde
> pend hewsonrel hewsonsens

Summary statistics data initialized.  Next use, in any order,

    ssd set observations (required)
        It is best to do this first.

    ssd set means (optional)
        Default setting is 0.

    ssd set variances or ssd set sd (optional)
        Use this only if you have set or will set correlations and,
even then, this is optional but
        highly recommended.  Default setting is 1.

    ssd set covariances or ssd set correlations (required)

.  ssd set obs `N'
number required
r(100);

Once I run the 'clear' command, it stops working.

Many thanks for your help, much appreciated.

Laura


On 13 March 2013 14:42, William Buchanan <william@williambuchanan.net> wrote:
>
> I don't think it's a problem with Stas's code:
>
> clear
> set obs 1000
> set seed 123412345
> loc thevars hewsonstrong hewsonknowo hewsonint hewsoninspi hewsonmoral hewsoncom hewsondecent hewsondepend hewsonrel hewsonsens
> foreach v of loc thevars {
>         qui: g id=runiform()
>         qui: sort id
>         /* Create categorical variables */
>         qui: egen `v' = cut(id), group(5)
>         /* Recode the variables to have a scale of 1-5 */
>         qui: replace `v'=`v'+1
>         qui: drop id
>         ta `v'
> }
> di `"`thevars'"'
> polychoric `thevars'
>
> You should get the matrix below:
>
> hewsonstrong   hewsonknowo     hewsonint   hewsoninspi   hewsonmoral     hewsoncom  hewsondecent  hewsondepend     hewsonrel    hewsonsens
> hewsonstrong             1
>  hewsonknowo     .00757784             1
>    hewsonint    -.01262061    -.02690757             1
>  hewsoninspi    -.02231892     .00686848    -.05248286             1
>  hewsonmoral    -.01757277     .03654591    -.01172315     .00876538             1
>    hewsoncom     .02118915    -.01551056    -.01772426    -.00254414    -.01837419             1
> hewsondecent    -.04116923     .01386142     .01676589     .02919821     .02132269    -.03298761             1
> hewsondepend    -.05280085    -.04659978     .04573638     .01585641     .06480197    -.01835768    -.02216604             1
>    hewsonrel     .02682836    -.00184872    -.00382025     .01606113    -.03550408     -.0348673     .06411171    -.02613873             1
>   hewsonsens     .02954704     -.0527784     .01723573    -.06313792     .00313384     .01654635     .02302709    -.00659043     -.0318338             1
>
>
>
>
> On Mar 13, 2013, at 7:21 AM, Laura Maria Schwirz <schwirzl@tcd.ie> wrote:
>
> > I am referring to a previous thread (RE: sem with categorical
> > variables, September 2012) as I have similar problems. I tried using
> > Stas' code for polychoric to sem analysis but the local command
> > appears to be a problem. If I type
> >
> >> local thevars hewsonstrong hewsonknowo hewsonint hewsoninspi hewsonmoral hewsoncom hewsondecent hewsondepend hewsonrel hewsonsens
> >> display `thevars'
> >> polychoric `thevars'
> > varlist required
> >
> > It as actually empty so i can't proceed with the polychor command
> > Any thoughts/ideas of where I am going wrong?
> >
> > Thanks,
> > Laura
> > *
> > *   For searches and help try:
> > *   http://www.stata.com/help.cgi?search
> > *   http://www.stata.com/support/faqs/resources/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/faqs/resources/statalist-faq/
> *   http://www.ats.ucla.edu/stat/stata/
>



--
Laura Schwirz

PhD Candidate and IRCHSS Scholar
Department of Political Science
Trinity College Dublin
Dublin 2
Republic of Ireland
Email: schwirzl@tcd.ie



--
Laura Schwirz

PhD Candidate and IRCHSS Scholar
Department of Political Science
Trinity College Dublin
Dublin 2
Republic of Ireland
Email: schwirzl@tcd.ie
*
*   For searches and help try:
*   http://www.stata.com/help.cgi?search
*   http://www.stata.com/support/faqs/resources/statalist-faq/
*   http://www.ats.ucla.edu/stat/stata/


© Copyright 1996–2014 StataCorp LP   |   Terms of use   |   Privacy   |   Contact us   |   Site index