Re: st: -warning: variables in at() list not found in model after mfx or mfx2

[Richard Williams <Richard.A.Williams.5@ND.edu>]

At 10:27 AM 7/20/2007, Mirko wrote:

> Both -mfx2- and �mfx- seem to work, but both the commands return a
> warning that reads:
>
> "-warning: variables z10 ...z30 in at() list not found in model-
>
> I checked repeatedly and those variables are (and must be) in the model.
>
> I then wondered if there was a maximum number that could be dealt with
> by the -at()- option. Playing with my model I found out that I stop to
> get that warning when I have less than 10 variables in -at()-
Without a replicable example it is hard to 
tell.  I wonder if a possible workaround would be 
to center your x1-x40 variables so they all had a 
mean of zero, e.g. using Ben Jann's -center- command, available from SSC,

center x1-x40 if !missing(y, x1-x40, z1-z30)

and then on mfx/mfx2 specify -at(zero)-.

I think this will work so long as x1 is 
continuous; if it isn't then you shouldn't center it.

If you try this, also try it with the set of 
fewer vars (where mfx/mfx2 currently work) and 
confirm that results are the same.


-------------------------------------------
Richard Williams, Notre Dame Dept of Sociology
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EMAIL:  Richard.A.Williams.5@ND.Edu
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