st: Computing z-scores with zanthro Issue

[Patrick Abi Nader <p0abin01@gmail.com>]

hello Stata users,

I am trying to compute z-scores for children's BMI data. I found the
zanthro package and downloaded it.
this is the code that I am using and I believe it is the correct one

"egen zbmi = zanthro(v3_bmi,ba,US), xvar(v3_chd_ageyears)
gender(gender)gencode(m=1, f=2) ageunit(year)"

v3_bmi is my bmi variable, ba is the growth chart for 2-20 years old
in the US, v3_chd_ageyears, is child age in year, and my gender
variable is also included.
after I run the code this is the error that I have received:

"using data not sorted r(5);"

So I sorted the data on the BMI variable and subsequently on the age
and ID variables and it still gave me the same error. Does anyone have
any suggestions?

Thanks
Patrick
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