random number generation and two DO%E2%80%A6END loops in sas

[mrahouma]

I need to Use SAS random number generation functions `RAND()` and a `DO....END loop` to create 100 obs in variable named X then I want to use another DO loop of 500 rounds to generate a total of 500 samples, each with 100 obs. a sample is basically sampling from a standard normal distribution.

I tried the following code but it does not give me what I need:

    data A;
    call streaminit(123);   /* set random number seed */
    do i = 1 to 100;
    X = rand("Normal");     /* random number generator */
     output;
    end;
    
    do r = 1 to 500 ;
    if i then X = rand("Normal");
    output;
    end;
    run;

Any input will be greatly appreciated.

[Reeza]

I think you're using observations/records here in a confusing fashion.
How many rows and columns are you expecting in your output data set?

[mrahouma]

Thanks for your time. @hashman has replied this. Appreciate your efforts.

[hashman · Accepted solution]

@mrahouma:

Do I understand you correctly that you want 50,000 records with random X where the first 100 have I=1, the next 100 have I=2, and so on till the last 100 with I=500? If so, you need to nest the DO loops, like so:  

data want ;                                                                                                                             
  call streaminit(123) ;                                                                                                                
  do I = 1 to 500 ;                                                                                                                     
    do _n_ = 1 to 100 ;                                                                                                                 
      X = rand ("normal") ;                                                                                                             
      output ;                                                                                                                          
    end ;                                                                                                                               
  end ;                                                                                                                                 
run ;     

Kind regards

Paul D.

[mrahouma]

Thanks a lot