Fig.1findit xbrcsplineinsheet using D:tgh.csvgenerate tgh= round(sleep , .01)generate tgh2=tgh2generate tgh3= tgh3mkspline tghs= tgh, nknots(4) cubic displayknotsmat knots=r(knots)generate tghp1= max(0,tgh-(-4)3generate tghp2= max(0,tgh-(-1)3generate tghp3= max(0,tgh-0.5)3generate tghp4= max(0,tgh-3)3stset t2, failure(at2dm=1) scale(1) stcox tghs*, cformat(%5.2f)testparm tghs*levelsof tghxbrcspline tghs, values(-13(0.05) 9) ref (-4) matkno
