Replicate results of -twoway lowess- with -lowess-

[Sebastian Geiger]

Dear all,

I'm trying to replicate the results retrieved by -twoway lowess- with the command -lowess-. The reason for is is that I need the smoothed data points to send them to another department.

Unfortunately, the results I get from -lowess- are not the same as from -twoway lowess- although I've specified the same options (bwidth etc.). Another soultion for my problem would be an option to save the results coming from -twoway lowess- to a variabel.

I would post a snapshot of my data but the precise reason why I'm trying to use -lowess- are confidality reasons.

My code looks as follows:

lowess krit2_surplus_max_bs_share_all krit2_surplus_max if krit2_surplus_max>=0 & krit2_surplus_max<=10000, bwidth(0.1)  gen(skrit2_surplus_max_bs_share_all )
lowess krit3_surplus_max_bs_share_all krit3_surplus_max if krit3_surplus_max>=0 & krit3_surplus_max<=10000, bwidth(0.1)  gen(skrit3_surplus_max_bs_share_all )
lowess krit4_surplus_max_bs_share_all krit4_surplus_max if krit4_surplus_max>=0 & krit4_surplus_max<=10000, bwidth(0.1)  gen(skrit4_surplus_max_bs_share_all )
lowess krit7_surplus_max_bs_share_all krit7_surplus_max if krit7_surplus_max>=0 & krit7_surplus_max<=10000, bwidth(0.1)  gen(skrit7_surplus_max_bs_share_all )

twoway  (line skrit2_surplus_max_bs_share_all  krit2_surplus_max if krit2_surplus_max<=10000, connect(stairstep) sort(Datum krit2_surplus_max) )    ///
        (line skrit3_surplus_max_bs_share_all  krit3_surplus_max if krit3_surplus_max<=10000, sort(Datum krit3_surplus_max) )    ///
        (line skrit4_surplus_max_bs_share_all  krit4_surplus_max if krit4_surplus_max<=10000, sort(Datum krit4_surplus_max) )    ///
        (line skrit7_surplus_max_bs_share_all  krit7_surplus_max if krit7_surplus_max<=10000, sort(Datum krit7_surplus_max) )    ///    
        if Datum==td(${selectdate}), subtitle("lowess") 

twoway  (lowess krit2_surplus_max_bs_share_all  krit2_surplus_max if krit2_surplus_max>=0 & krit2_surplus_max<=10000, bwidth(0.1) sort(Datum krit2_surplus_max) )    ///
        (lowess krit3_surplus_max_bs_share_all  krit3_surplus_max if krit3_surplus_max>=0 & krit3_surplus_max<=10000, bwidth(0.1) sort(Datum krit3_surplus_max) )    ///
        (lowess krit4_surplus_max_bs_share_all  krit4_surplus_max if krit4_surplus_max>=0 & krit4_surplus_max<=10000, bwidth(0.1) sort(Datum krit4_surplus_max) )    ///
        (lowess krit7_surplus_max_bs_share_all  krit7_surplus_max if krit7_surplus_max>=0 & krit7_surplus_max<=10000, bwidth(0.1) sort(Datum krit7_surplus_max) )    ///    
        if Datum==td(${selectdate}), subtitle("twoway lowess")

I attach the comparision of results. Notably the -twoway lowess- graph remains at zero for a longer in the beginning - this is the expected result. Also it is more smooth than the pure -lowess- command.