topic Re: Split datasets into multiple small datasets in SAS Programming

Split datasets into multiple small datasets

adityaa9z — Thu, 05 Jul 2018 06:02:35 GMT

Hi all,

I want to understand how can I split a dataset into multiple datasets in different percentages.

Say I have a dataset Have and I want to split it into first 20% and rest equally into 3 parts.

Thanks in advance

Re: Split datasets into multiple small datasets

andreas_lds — Thu, 05 Jul 2018 06:56:13 GMT

I am sure that this question was asked many times before and almost always somebody answered: "why? Splitting data is a good idea in very, very few cases, only."

Some hints:

the set-statement has the options "nobs" - useful to know how many obs are in a dataset
the automatic variable _n_ is necessary to trigger the right output-statement
because the output-statement does not allow dynamic naming of the dataset to write to, you have to code one output-statement for each dataset to be created
each dataset has to be named in the data-statement

Re: Split datasets into multiple small datasets

PeterClemmensen — Thu, 05 Jul 2018 07:15:05 GMT

I agree with @andreas_lds, hardly ever a good idea.

However if you want to do it anyways, here is a nice example of how

Creating Quantile Groups

Re: Split datasets into multiple small datasets

RW9 — Thu, 05 Jul 2018 07:31:44 GMT

First off, its generally better to not do so, assigning groups within the one dataset creates easier programming down the line.

If you wish to continue then surveyselect should be able to do it:

https://support.sas.com/documentation/cdl/en/statug/63033/HTML/default/viewer.htm#surveyselect_toc.htm

Which was mentioned in:

https://communities.sas.com/t5/Base-SAS-Programming/Subsetting-Dataset-based-on-number-of-observations/m-p/475165#M122166

Re: Split datasets into multiple small datasets

PaigeMiller — Thu, 05 Jul 2018 10:53:13 GMT

I feel like joining the party!

Don't split your data sets!

Re: Split datasets into multiple small datasets

Ksharp — Thu, 05 Jul 2018 13:11:44 GMT

data x1 x2 x3 x4;
 set sashelp.air;
 call streaminit(123456789);
 _id_=rand('table',0.2,0.8/3,0.8/3);
 if _id_=1 then output x1;
  else if _id_=2 then output x2;
    else if _id_=3 then output x3;
      else if _id_=4 then output x4;
run;