只是输入 ml maximize 是会提示you must issue -ml model- first
但是我按书上的例子:
. program myprobit_lf
1. version 9.1
2. args lnf xb
3. quietly replace 'lnf' = ln(normal('xb')) if $ML_y1==1
4. quietly replace 'lnf' = ln(normal(-'xb')) if $ML_y1==0
5. end
. sysuse cancer,clear
(Patient Survival in Drug Trial)
. gen drug2=drug==2
. gen drug3=drug==3
. ml model lf myprobit_lf (died=drug2 drug3 age)
. ml maximize
' invalid name
r(198);
这个是哪里有什么问题吗?