I am currently struggling a bit with Stata syntax. As I am using the "margins" command, I want to specify an option. The following is from the "help margins":

at(age=(20(10)50)) does the same as at(age=(20 30 40 50)); that is,
you may specify a numlist.
If I do not want to hardcode the numeric values into the numlist, but want to have it dynamic, how can I do that? So for example, I want the numlist to go from min(age) to max(age) in 10 even steps. Or alternatively, I want to go from one standard deviation below mean to one standard deviation above mean in 3 even steps.

I feel like I probably cannot do this within the parenthesis of margins, but even when trying to construct a numlist prior to the margins account with these values, it seems that I am constantly failing at the syntax. "help numlist" isn't that helpful for me, as it only gives hardcoded numbers.