Hi experts,
Today I try to find a way to generate a variable called logTAT1.

Normally, logTAT1= ln(TAT)
When the value of TAT-0, I will use the min value of TAT instead

So, my code is:

Code:
      gen logTAT1=.
      replace logTAT1 = ln(TAT)
      replace logTAT1 = ln(min(TAT)) if TAT=0
However, it resutls in an error.

Code:
invalid syntax
r(198);

end of do-file

r(198);

Could you please help me to sort it out? Thank you.