st: Re: Graph interaction of two countinous variables

[Maarten Buis <maartenlbuis@gmail.com>]

On Thu, Oct 18, 2012 at 12:02 PM, D.V.Vo wrote me privately:

> I am Dut, a PhD student at University of Groningen, the Netherlands. I think
> you have much experience about the graph interaction in Stata through the
> forum. Therefore, I would like to ask your favor to share that experience
> with me. Could you please help me about this?
> I have the logistic and tobit  regression models:
>  1. Logit (Y) = X1 (continuous variable) + X2 (continuous variable) + X1*X2
> + control variables
>  2. Logit (Y) = X1^2 (continuous variable) + X2 (continuous variable) +
> X1^2*X2 + control variables
>  3. Tobit (Y) = X1 (continuous variable) + X2 (continuous variable) + X1*X2
> + control variables
>  4. Tobit (Y) = X1^2 (continuous variable) + X2 (continuous variable) +
> X1^2*X2 + control variables
>  These independent and moderate variables are standardized, with these
> models, after regression, how can I graph the interaction effects in Stata?
> Could you please share with me about specific command in Stata that could do
> these for me?
> In the case, the above independent and moderate variables are not
> standardized, how can I graph the interaction effects in Stata for this
> case?

Such questions need to be sent directly to Statalist, not its
individual members. For reasons why that is the case see:
<http://www.stata.com/support/faqs/resources/statalist-faq/#private>.
That FAQ gives you all the information you need on how to join and how
to ask questions on the list.

There is a whole set of examples on how to do what you ask for various
versions of Stata here:
<http://www.maartenbuis.nl/wp/inter_quadr/inter_quadr.html>.

You seem to add x1^2 without adding x1; that seems unusually
restrictive and probably wrong.

-- Maarten

---------------------------------
Maarten L. Buis
WZB
Reichpietschufer 50
10785 Berlin
Germany

http://www.maartenbuis.nl
---------------------------------
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