st: adjusted fitted-line/scatter plot after bootstrap with CI

[Juan Dominguez <juan.dominguez@monash.edu>]

Dear Statalist,

I am fitting a model with a quadratic term (reg DV IV IV^2 COVs) and I
would like to graph the quadratic relationship after adjustment for
covariates and bootstrapping with confidence interval envelope much as
fracplot does after fracpoly.

I tried cprplot but it won't work with bootstrap and won't add CI. In
addition, cprplot will draw a straight line rather than a curve
describing the quadratic relationship. The lowess option does not
yield a satisfactory curve like fracplot. acprplot will run after
bootstrapping (as in reg DV IV IV^2 COV, vce(boot, boot_options)), but
just like cprplot, it won't graph the quadratic curve and won't
include the CI envelope.

Is there a way to accomplish this using qfitci?

Best next thing is predxcon and while it does display a line fitted to
predicted values it can't be used in combination with bootstrap and it
won't include the associated scatter plot.

In a previous posting on this list for a similar query it was
suggested to manually predict y and se after the adjusted regression,
and draw the regression line with ci's on top of the scatterplot. I
know how to predict y and se but I don't know how to draw the
subsequent (curved) regression line with ci's.

Your help on this issue is much appreciated.

Regards,

Juan
*
*   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/