set obs 450
mat input B=(1,0.85,0.76,0.91\0.85,1,0.12,-0.15\0.76,0.12,1,-0.13\0.91,-0.15,-0.13,1)
drawnorm y x1 x2 x3,means(3,5,6,5) sd(0.84,0.86,1.8,2.3) corr(B)
B not positive (semi)definite