Generate two-dimensional array with random binomial data

[Dinurik]

Dear SAS Programmers,

How do I generate an array and fill it with random binomial data? 

Say, I need an array with 100 rows and 5 columns, and I want the probability to be equal in all columns, say p=0.1.

My current code (sorry, if it's totally stupid) is:

data Table (keep=aids);
call streaminit(4321);
array p[5] _temporary_ (repeat(0.1, 5));
do i = 1 to 500;
aids = rand("Table", of p[*]);
output;
end; end;
run;

First of all, the repeat function in the array does not work (because it probably shouldn't be there). But when I replace it with (0.1, 0.1, 0.1, 0.1, 0.1) the code produces a single variable with 500 entries instead of arranging the results in an array. 

Thank you!

[Reeza · Accepted solution]

data want;

array col(5);

do nrows=1 to 100;

    do i=1 to dim(col);

           col(i) = rand('binomial', 0.1);

      end;

     output;

end;

run;

Depends a bit on what you mean by 

I want the probability to be equal in all columns, say p=0.1.

Random usually means that you won't have equal distributions, but the probability should be 0.1 across all observations anyways, dependent on sample size of course.

---

@Dinurik wrote:

Dear SAS Programmers,

How do I generate an array and fill it with random binomial data? 

Say, I need an array with 100 rows and 5 columns, and I want the probability to be equal in all columns, say p=0.1.

My current code (sorry, if it's totally stupid) is:

data Table (keep=aids);
call streaminit(4321);
array p[5] _temporary_ (repeat(0.1, 5));
do i = 1 to 500;
aids = rand("Table", of p[*]);
output;
end; end;
run;

First of all, the repeat function in the array does not work (because it probably shouldn't be there). But when I replace it with (0.1, 0.1, 0.1, 0.1, 0.1) the code produces a single variable with 500 entries instead of arranging the results in an array. 

Thank you!

---

[Dinurik]

Hi Reeza,

Thanks a lot. I tried:

data want;
     call streaminit(4321);
     array col(5);
       do nrows=1 to 100;
          do i=1 to dim(col);
          col(i) = rand('Bernoulli', 0.1);
       end;
  output;
  end;
run;

And it worked. 

Is there any resource/article, that you could refer me to so I can teach myself on this topic?

[Reeza]

Simulating data or just generate data step logic?

For simulating data, Rick Wicklins blog and book are the best references:

https://www.amazon.ca/Simulating-Data-SAS-Rick-Wicklin/dp/1612903320

---

@Dinurik wrote:

Is there any resource/article, that you could refer me to so I can teach myself on this topic?

---

[Dinurik]

Thanks so much! 

What about data step logic? Data step completely throws me off, so I would really appreciate any recommendation of what to read =). 

[Reeza]

@novinosrin may have better suggestions. I'm an older user (before StackOverflow, FB or Twitter) so learned via reading the documentation.  

Which I would actually highly recommend. 

https://documentation.sas.com/?docsetId=lrcon&docsetTarget=n1lw46l098rlqsn1948oua32fnsl.htm&docsetVe...

[Dinurik]

Wonderful, thanks!