Notice: On April 23, 2014, Statalist moved from an email list to a forum, based at statalist.org.
From | Joerg Luedicke <joerg.luedicke@gmail.com> |
To | statalist@hsphsun2.harvard.edu |
Subject | Re: st: Test for significance of the difference between knee locations? |
Date | Thu, 18 Oct 2012 22:21:43 -0500 |
Nice, thanks! Joerg On Thu, Oct 18, 2012 at 9:32 PM, Austin Nichols <austinnichols@gmail.com> wrote: > Joerg Luedicke <joerg.luedicke@gmail.com>: > Stata 12 allows you to test coefs that have no corresponding variables > in the data; Stata 11 gives an error msg, so you must instead: > test _b[k1]==_b[k2] > > On Thu, Oct 18, 2012 at 6:12 PM, Joerg Luedicke > <joerg.luedicke@gmail.com> wrote: >> I was just putting together some example code, similar in principle to >> Austin's code, but encountered difficulties with the -test- command. >> If we use Austin's code: >> >> *--Austin Nichols' code-- >> sysuse nlsw88, clear >> *compare extremum positions for quadratics, e.g. for >> *tw qfit wage age if union==0||qfit wage age if union==1 >> reg wage c.age##c.age##i.union, nohe >> loc 1 (k1:-_b[age]/_b[c.age#c.age]/2) >> loc 2 (k2:-(_b[age]+_b[1.union#c.age])/ >> loc 2 `2'(_b[c.age#c.age]+_b[1.union#c.age#c.age])/2) >> nlcom `1' `2', post >> test k1==k2 >> *------------------------------- >> >> I get an error message after -test k1==k2-: >> >> . test k1==k2 >> k1 not found >> r(111); > * > * For searches and help try: > * http://www.stata.com/help.cgi?search > * http://www.stata.com/support/faqs/resources/statalist-faq/ > * http://www.ats.ucla.edu/stat/stata/ * * For searches and help try: * http://www.stata.com/help.cgi?search * http://www.stata.com/support/faqs/resources/statalist-faq/ * http://www.ats.ucla.edu/stat/stata/