-yline()- is strict: it needs a numlist. However, you can do calculations on the fly using a standard construct.
rvfplot, yli(`=-2*e(rmse)' `=2*e(rmse)')
The `=exp' syntax is explained at -help macro-.
If you type `=2 * e(rmse)', for example, Stata reads this as
1. Do the calculation 2 * e(rmse)
2. Insert the result at this place so that the command being typed can see it.
Thus -yline()- is pretty dumb and certainly contains no hidden calculator, but the rest of Stata is up to doing what you want.
As usual, start with a left quote ` and finish with a right quote '.
Nick
[email protected]
From: Lachenbruch, Peter [mailto:[email protected]]
I am using rvfplot to graph residuals and I would like to draw lines at -2 sd and 2 sd limits.
My thought was to use rvfplot, yline(-2*e(rmse) 2*e(rmse))
But Stata did not like it:
. rvfplot,yline(2*e(rmse) 2*e(rmse))
invalid line argument, -2*(e(rmse) 2*e(rmse)
r(198);
I tried setting the limits to a scalar or a local scalar, but I got the same result (I had set scalar L= 2*e(rmse) )
.rvfplot,yline(-L L)
invalid line argument, -L L
r(198)
Is there a way to do this or does yline require numbers rather than functions?
I could do several twoway plots (one for residuals,one for the upper limit, one for the lower limit), but this seems a bit cumbersome
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