topic Re: Variable format in SAS Programming

Variable format

wschnell1 — Mon, 18 Nov 2013 04:21:37 GMT

Hi,

I have several variables and would like to change the format of one of the variables. I have tried the following code but am having some trouble getting it to work

The variable I am trying to change to format 8. is called firmid

data sub_sample_1986;

format firmid 8.;

run;

Any help is appreciated

Cheers

Re: Variable format

Tal — Mon, 18 Nov 2013 06:07:40 GMT

Are you sure you r not missing a set statement in your code?

Re: Variable format

ballardw — Mon, 18 Nov 2013 16:47:22 GMT

Proc datasets will let you change characteristics of variables such as label and fomrat in place without creating a new data set.

proc datasets library=<library the dataset is in> ;

modify sub_sample_1986;

format firmid 8.; /*put as many variable name format combinations as you need here*/

run;

quit;

Re: Variable format

Tal — Mon, 18 Nov 2013 18:05:31 GMT

is your code ballardw as efficient as this below? Just curious

data sub_sample;

modify sub_sample;

format firmid 8.; run;

Re: Variable format

ballardw — Mon, 18 Nov 2013 20:05:38 GMT

Define "efficient" in this case. I think using MODIFY you're going through all of the observations in the data set, so execution time is going to depend on the number of records. With Proc datasets only the data set descriptor is affected and it takes basically the same amount of time to run with 10 records or 10billion.

Modify is intended to modify, append or delete observations from a data set, in other words change the content.

It is worth remembering the note in the SAS documentation:

Damage to the SAS data set can occur if the system terminates abnormally during a DATA step that contains the MODIFY statement.

Observations in native SAS data files might have incorrect data values, or the data file might become unreadable.

Proc Datasets as called in this above manner only changes the descriptions of the variables: name, format, informat or label and will not actually change values or the number of observations.

Re: Variable format

Tal — Tue, 19 Nov 2013 01:24:37 GMT

right,he just wanted to change the format not modify the entire data.

Thanks for the explanation