topic Re: Writing a do loop macro to find a string and increment in SAS Programming

Writing a do loop macro to find a string and increment

tjc87 — Wed, 07 Feb 2018 22:57:01 GMT

Can a global macro be created that will read in a file, increment the suffix of file name by 1 then read in the updated file name, and repeat this for a set number of files?

For example, I have 100 files that are named 'scores001' 'scores002' 'scores003'...'scores100' that need to be read into SAS then saved to a permanent 'scorestotal' file. These files have .dat extensions.

I've tried to use a %macro do loop but the problem is the file names are written in several places throughout my code. I would need a macro that finds the name 'scores' then appends numbers dynamically and saves the output to a permanent file.

The three lines of the code that need to be updated:

filename class &scores1;

data scores1;

if _n_=1 then set param; set scores1;

I'm using SAS 9.4 X64_8PRO platform on a Windows version 6.2.9200

Thanks for your time!

Re: Writing a do loop macro to find a string and increment

Reeza — Wed, 07 Feb 2018 23:05:53 GMT

Don't. Import all in one step instead. Unless they're really big files. In that case a macro loop is quite easy:

%macro loop_nums(start=, end=);

    %do i=&start %to &end;

        %let index_counter = %sysfunc(putn(&i, z3.)); 

        %put &index_counter;

    %end;


%mend;

%loop_nums(start=10, end=105);

EDIT: Instructions on how to import all at once:

https://communities.sas.com/t5/SAS-Communities-Library/How-do-I-write-a-macro-to-import-multiple-text-files-that-have/ta-p/223627

If you're having difficulty post your code.

@tjc87 wrote:

Can a global macro be created that will read in a file, increment the suffix of file name by 1 then read in the updated file name, and repeat this for a set number of files?

For example, I have 100 files that are named 'scores001' 'scores002' 'scores003'...'scores100' that need to be read into SAS then saved to a permanent 'scorestotal' file. These files have .dat extensions.

I've tried to use a %macro do loop but the problem is the file names are written in several places throughout my code. I would need a macro that finds the name 'scores' then appends numbers dynamically and saves the output to a permanent file.

The three lines of the code that need to be updated:

filename class &scores1;

data scores1;

if _n_=1 then set param; set scores1;

I'm using SAS 9.4 X64_8PRO platform on a Windows version 6.2.9200

Thanks for your time!

Re: Writing a do loop macro to find a string and increment

Reeza — Wed, 07 Feb 2018 23:05:06 GMT

Replace your string with the macro variable so you're not replacing strings, the macro variable has changed and the code will loop through with that new number.

Re: Writing a do loop macro to find a string and increment

ballardw — Thu, 08 Feb 2018 00:28:51 GMT

The DAT file extension has no standard meaning so that really doesn't help. Many people and/or programs use it for "data" and are stuck back when DOS limited the extensions to 3 characters. But the content could be text, fixed column, delimited, named, or a proprietary binary format.

One of the "meanings" for DAT extensions was also "Digital Audio Tape" which was a high definition sound format. I doubt that is what you have though.

Re: Writing a do loop macro to find a string and increment

tjc87 — Thu, 08 Feb 2018 20:45:53 GMT

The .dat files are text files with 3 rows of numeric values.

Re: Writing a do loop macro to find a string and increment

Reeza — Thu, 08 Feb 2018 20:51:15 GMT

@tjc87 wrote:

The .dat files are text files with 3 rows of numeric values.

Then you should really use the approach I linked to that will import all at once and identify the source. Its the most efficient method. And no macros.

Re: Writing a do loop macro to find a string and increment

tjc87 — Thu, 08 Feb 2018 21:34:47 GMT

The 'wildcard import all files in a folder' solution worked! I appreciate your help!