# st: AW: Plotting 3 way continuous interactions in regression

 From "Martin Weiss" To Subject st: AW: Plotting 3 way continuous interactions in regression Date Thu, 13 Aug 2009 14:06:10 +0200

```<>

You use "_SAP" in your -regress- command, but "SAP" in your -global-s....

What exactly does Stata say after which command?

HTH
Martin

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Von: owner-statalist@hsphsun2.harvard.edu
[mailto:owner-statalist@hsphsun2.harvard.edu] Im Auftrag von Kris Anderson
Gesendet: Donnerstag, 13. August 2009 01:54
An: statalist@hsphsun2.harvard.edu
Betreff: st: Plotting 3 way continuous interactions in regression

Hi,

I am stuck on a piece of code that I can't seem to debug. I am trying to
plot a 3-way interaction using the FAQ on plotting these interactions
with covariates. The code hangs up as I try to compute 4 simple slopes.
The program tells me the name of my interaction term is invalid. Can
anyone see a problem here? I tried renaming the variable but it didn't help.

Thanks

regress avgdrink age sex gradedich white hisp csocanx caffil cpn SAF SP
AP _SAP if currentdrinker > 0

sum csocanx
global hi=r(max)
global lo=r(min)
sum caffil
global HAF=r(mean)+r(sd)
global LAF=r(mean)-r(sd)
sum cpn
global HPN=r(mean) +r(sd)
global LPN=r(mean) -r(sd)
sum age
global mage=r(mean)
sum white
global mwhite=r(mean)
sum hisp
global mhisp=r(mean)
global HPNHAF "csocanx + (\$HPN)*SP + (\$HAF)*SAF + (\$HPN)*(\$HAF)*SAP"
global HPNLAF "csocanx + (\$HPN)*SP + (\$LAF)*SAF + (\$HPN)*(\$LAF)*SAP"
global LPNHAF "csocanx + (\$LPN)*SP + (\$HAF)*SAF + (\$LPN)*(\$HAF)*SAP"
global LPNLAF "csocanx + (\$LPN)*SP + (\$LAF)*SAF + (\$LPN)*(\$LAF)*SAP"
lincom \$HPNHAF /* slope 1*/
global b1 = r(estimate)
lincom \$HPNLAF /* slope 2*/
global b2 = r(estimate)
lincom \$LPNHAF /* slope 3*/
global b3 = r(estimate)
lincom \$LPNLAF /* slope 4*/
global b4 = r(estimate)

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