Error: invalid name r(198);

[Lumanie Bird]

Hi everyone,

I'm writing this function which helps to generate a one to one mapping of two identifiers by the help of their firm names' start and end dates.

---

cap prog drop create_unique_match
prog def create_unique_match

args unique_firm min_date_uniq max_date_uni count_firm min_date_c max_date_c

gen tag_date = 1 if (`min_date_uni' >= `min_date_c' & `min_date_uni' <= `max_date_c')
replace tag_date = 1 if (`max_date_uni'>=`min_date_c' & `max_date_uni'<=`max_date_c')
replace tag_date = 0 if mi(tag_date)
bys `unique_firm': egen flag_date = max(tag_date)
keep if tag_date==flag_date


bys `unique_firm': egen max_simi_score = max(simi_score)
keep if simi_score==max_simi_score

duplicates drop `unique_firm', force

end

---

and then I ran the following code:

---

create_unique_match assignee_id min_ee_name_dt max_ee_name_dt permco min_listed_dt max_listed_dt

---

Then it reports:
<=max_listed_dt invalid name
r(198);

But if I go back to my data without using the function but instead:

---

local min_date_uni min_ee_name_dt
local max_date_uni max_ee_name_dt
local min_date_c min_listed_dt
local max_date_c max_listed_dt

gen tag_date = 1 if (`min_date_uni' >= `min_date_c' & `min_date_uni' <= `max_date_c')

---

it doesn't report any error.

Could anybody help me with this? Many thanks!

Best,
Luman

[Nick Cox]

You can't abbreviate local macro names. With your args statement you created a local macro with name min_date_uniq and so min_date_uni is at best the name of a different local macro. As it doesn't exist, the macro reference doesn't produce the result you want.

Change the name to min_date_uni and things should work better.

Strictly, you're writing a program defining a command; neither is a function in Stata terms.

[Lumanie Bird]

Thank you so much Nick! I didn't realize this. And also thank you for correcting me with the Stata terms