*******************
sysuse auto
preserve
loc s=0
mat b=J(19,4,.)
forv i=0.05(0.05)1{
loc s=`s'+1
qreg price weight length foreign , q(`i')
predictnl b=_b[weight], ci(lo up)
mat b[`s',1]=`i'
mat b[`s',2]=b[1]
mat b[`s',3]=lo[1]
mat b[`s',4]=up[1]
drop b lo u
}
clear
svmat b
tw rarea b3 b4 b1||scatter b2 b1,c(l)
restore
*********************
我感觉程序应该是这样的:
*******************
sysuse auto
preserve
loc s=0
mat b=J(19,4,.)
forv i=0.05(0.05)1{
loc s=`s'+1
qreg price weight length foreign , q(`i')
predictnl b=_b[weight], ci(lo up)
mat b[`s',1]=`i'
mat b[`s',2]=b[1]
mat b[`s',3]=lo[1]
mat b[`s',4]=up[1]
drop b lo u
p
}
clear
svmat b
tw rarea b3 b4 b1||scatter b2 b1,c(l)
restore
*********************