Notice: On April 23, 2014, Statalist moved from an email list to a forum, based at statalist.org.

# Re: st: RE: graph interaction curve

 From Fabio Zona <[email protected]> To [email protected] Subject Re: st: RE: graph interaction curve Date Fri, 25 Feb 2011 19:20:42 +0100 (CET)

```does this solution work only with the functions c. ## ??
can I calculate the interactions as products of variables (standardized variables) and the apply this method? If so, why doesn't it work with me?
f

----- Messaggio originale -----
Da: "Nick Cox" <[email protected]>
A: "[email protected]" <[email protected]>
Inviato: Venerdì, 25 febbraio 2011 17:27:18 GMT +01:00 Amsterdam/Berlino/Berna/Roma/Stoccolma/Vienna
Oggetto: st: RE: graph interaction curve

The short answer is No. There isn't an easy way, but there is a way to solve this nevertheless. Maarten already posted a concrete example at

http://www.stata.com/statalist/archive/2011-02/msg01240.html

That is, get a series of predictions for different values of the moderator and plot them as a series of lines in the (X, Y) space.

So, the same question gets the same answer.

Otherwise we need to see something new from you, e.g. specific detail on how you wrote code that doesn't work, etc.

Nick
[email protected]

Fabio Zona

I am really having hard time to graph an interacion between a curve and a linear moderator.

this is the equation:

Y = a + X +  X^2  + moderator  +  X * moderator

Is there an easy way to graph the curve and see how it changes, for different values of the moderator?

Also, I have another equation (more complex) with the same challenge:
Y = a + X +  X^2  + moderator  +  X*moderator  + X^2 * moderator

*
*   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/

*
*   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/
```