topic Need help with creating a do loop in SAS Programming

Need help with creating a do loop

amitsas — Mon, 19 Mar 2012 20:26:02 GMT

Hi,

I am hoping someone can help with request.

I need to create (say) 5 tables or data sets, for 5 states - CA, VA, NY, TX and OK

Each table has some information based on some criteria (say, name of state and its population). So the table for California looks like

CA 34,000,000

I can have a data step to do this, but I want to put the names of states in a marco variable string along with a do loop so that the do loop runs and creates a data step for each state in the macro variable string,

for example

%LET STATE = CA VA NY TX OK;

do loop (CA)

followed by

do loop VA etc..

Thanks to all who try to help.

Need help with creating a do loop

PGStats — Mon, 19 Mar 2012 20:31:30 GMT

Is this a homework? What have you tried so far?

Need help with creating a do loop

amitsas — Mon, 19 Mar 2012 20:36:26 GMT

This is not a homework.

I haven't used SAS in a while. I have a list of close to 2000 values for which I have retrieve some data. And I do not want to run the code 2000 times, based on each value.

From what i remember when I did do it, I used a long character string as a macro variable, and resolved the value by moving the do loop counter by 1 and then ran the code.

Need help with creating a do loop

PGStats — Mon, 19 Mar 2012 20:55:50 GMT

What you want would like this, I guess :

options mprint;

%LET STATES = CA VA NY TX OK;

%macro doloop(values);
%let i = 1;
%do %while(%length(%scan(&values,&i)) > 0);
%let value=%scan(&values,&i);
data _&value.;
t = "&value";
run;
%let i = %eval(&i+1);
%end;
%mend;

%doLoop(&STATES);

Need help with creating a do loop

amitsas — Mon, 19 Mar 2012 21:39:22 GMT

Thanks a lot! This works. This is very similar to how I did it originally.

The only change needed is probably in the %scan function. Right now it is only using the C from CA (and N from NY etc) fwhen resolving

%let value=%scan(&values,&i);,

while it needs to use the whole CA.I can probably take care of that.

Need help with creating a do loop

PGStats — Mon, 19 Mar 2012 21:46:58 GMT

%SCAN is supposed to extract a word, not just a letter. In my tests, 5 datasets were created : _CA, _VA, _NY, _TX, and _OK. Can you post your macro?

Need help with creating a do loop

amitsas — Mon, 19 Mar 2012 21:48:31 GMT

I just ran your macro without making any changes. But if you open the dataset, the value inside is C and not CA

Need help with creating a do loop

PGStats — Mon, 19 Mar 2012 21:52:20 GMT

It just looks that way in FSVIEW. Expand the column width and you will see that the whole value (2-letter) is there.

Need help with creating a do loop

amitsas — Mon, 19 Mar 2012 21:54:20 GMT

Sorry for my ignorance, and thank you again!

Need help with creating a do loop

PGStats — Mon, 19 Mar 2012 21:59:07 GMT

You're welcome. Cheers!