Precisions and counts

Question

I am working with a educational dataset called IPEDS from the National Center for Educational Statistics. They track students in college based upon major, degree completion, etc

Answer 1

This minimal example confirms your problem. (See, by the way, https://stackoverflow.com/help/mcve for advice on good examples.)

* code 
clear
input code 
14.2501 
14.2501 
14.2501 
end 

tab code if code == 14.2501
tab code if code == float(14.2501)

* results 
. tab code if code == 14.2501
no observations

. tab code if code == float(14.2501)

       code |      Freq.     Percent        Cum.
------------+-----------------------------------
    14.2501 |          3      100.00      100.00
------------+-----------------------------------
      Total |          3      100.00

The keyword is one you use, precision. In Stata, search precision for resources, starting with blog posts by William Gould. A decimal like 14.2501 is hard (impossible) to hold exactly in binary and the details of holding a variable as type float can bite.

It's hard to see what you're doing with your last block of code, which you don't explain. The last statement looks puzzling, as you're adding strings. Consider what happens with

. gen whatever =  "14.2501" + "14.3901" + "15.0999" + "40.0601"

. di whatever[1]
14.250114.390115.099940.0601

The result is a long string that cannot be a valid cipcode. I suspect that you are reaching towards

 ... if inlist(cipcode_str, "14.2501", "14.3901", "15.0999", "40.0601") 

which is quite different.

But using float() is the minimal trick for this problem.