# Re: st: RE: Graphing quadratic relationship

 From Austin Nichols <[email protected]> To [email protected] Subject Re: st: RE: Graphing quadratic relationship Date Sun, 27 Sep 2009 08:59:34 -0400

```But compare:

ssc inst locpr, replace
locpr died age, l c leg(off) loptions(leg(off))

You can also can change a few lines in -locpr- to add a quadratic option:

prog locpr2, sortpreserve
version 11.0
*/ coptions(string) Stub(str) SCatter Logit lbw BWidth(real 0) /*
if "`quadratic'"=="" logit `1' `2' if `touse' `wt'
else logit `1' c.`2'##c.`2' if `touse' `wt'

On Fri, Sep 18, 2009 at 5:35 PM, Hugh Robinson
<[email protected]> wrote:
> Stephanie,
>
> The cancer.dta data doesn't fit a quadratic very well, but do you mean something like this?  Coding is stata 9.2.
>
> sysuse cancer
> gen age2= age* age
> logit died  age age2
> predict yhatdied
> twoway (histogram age if (died == 1), percent yaxis(2) fcolor(sand) lcolor(none) legend(label(1 "Died")))(histogram age if (died==0), percent yaxis(2) fcolor(none) lcolor(black) legend(label(2 "Alive")))(connected yhatdied age, sort), xtitle(age) ytitle(probability death) legend(on) scheme(s2color) name(test)
>
> HR
>
>
> -----Original Message-----
> From: [email protected] [mailto:[email protected]] On Behalf Of Stephanie L Kent
> Sent: Friday, September 18, 2009 11:36 AM
> To: [email protected]
> Subject: st: Graphing quadratic relationship
>
> Dear users,
>
> I would like to graph a relationship between a quadratic independent
> variable and my dependent variable to see how y varies acccording to x and
> x^2.  It's a logistic regression so my DV is 0-1 and I need to show how
> both the 0's and 1's vary according to x and x^2.  Any advice on how to get
> started is much appreciated!
>
> Sincerely,
> Stephanie
>

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```