Creating State variables from city codes

[JuanA Samper]

Dear All,

I am trying to create a new "state" variable from certain city codes, one can observe that each city code has its own state number at the beginning. For example, 5 is state A and 99 is state Z. I was wondering if it is possible to extract the first (or first two) numbers from a city code and from that, create a new variable which assigns it to a state. I realize this is possible but due to my unfamiliarity with loops I would like to ask for anybody's help.

Thank you very much.

Juan

[William Lisowski]

It is indeed possible, as you realize, and it doesn't require loops, as you seem to believe, but in any event the exact technique depends very much on the specific format of your data.

Even the best descriptions of data are no substitute for an actual example of the data. There are many ways your data might be organized that are consistent with your description, and each would require a somewhat different approach. In order to get a helpful response, you need to show some example data.

Be sure to use the dataex command to do this. If you are running version 15.1 or a fully updated version 14.2, dataex is already part of your official Stata installation. If not, run ssc install dataex to get it. Either way, run help dataex and read the simple instructions for using it. dataex will save you time; it is easier and quicker than typing out tables. It includes complete information about aspects of the data that are often critical to answering your question but cannot be seen from tabular displays or screenshots. It also makes it possible for those who want to help you to create a faithful representation of your example to try out their code, which in turn makes it more likely that their answer will actually work in your data.

When asking for help with code, always show example data. When showing example data, always use dataex.

[JuanA Samper]

Dear William, thanks for the suggestion, I've included an example of the city codes below:

* Example generated by -dataex-. To install: ssc install dataex
clear
input double codmpio
5001
5002
5004
5021
52233
52234
52235
52236
63470
63471
63472
63473
68264
68263
68265
68266
70823
70824
70825
70826
end

Where the first code, 5, corresponds to state 5. 52 to state 52, 63 to state 63 and so on. The state dataset is unavailable but I wish to create one from the data. I hope this helps. The point is creating a command so as to assign these city codes to a different state.

[Clyde Schechter]

gen state_code = floor(codmpio/1000)