Hello,
I have continuous variables age and BMI. I need to apply this but I do not understand what it means:

Code:
double dage = age;
dage=dage/10;
double age_1 = pow(dage,-2);
double age_2 = dage;
double dbmi = bmi;
dbmi=dbmi/10;
double bmi_1 = pow(dbmi,-2);
double bmi_2 = pow(dbmi,-2)*log(dbmi);
Can anyone advise how I do this in stata? I do not understand why the age and bmi have been split into two variables age_1 and age_2 and how I create this in stata?