topic Re: assign random numbers in SAS Programming

assign random numbers

thanikondharish — Sat, 11 Aug 2018 02:41:22 GMT

data s ;
input name $ 15. ;

cards ;
dfsdfdas
dfsdfasdf
sdfwtrw
ghjghj
fghfdh
etwrt
rtyurtuy
rtrt
rtrysrt
rtrrt
;
run;

how to assign random numbers like below table ?

name	random
dfsdfdas	1
dfsdfasdf	2
sdfwtrw	1
ghjghj	2
fghfdh	1
etwrt	2
rtyurtuy	1
rtrt	2
rtrysrt	1
rtrrt	2

Re: assign random numbers

hashman — Sat, 11 Aug 2018 03:42:56 GMT

@thanikondharish:

I fail to observe any "randomness" in your assigned numbers. You merely assign 1 and 2 to the records whose observation numbers are odd and even, respectively. All you need to do to achieve that is:

data r ;                  
  set s ;        
  random = 2 - mod (_n_, 2) ;
run ;

However, if you really need RANDOM to be random in the [1:2] range, it should instead be:

data r ;                             
  set s ;                   
  random = ceil (rand ("uniform") * 2) ;
run ;

Paul D.

Re: assign random numbers

ballardw — Mon, 13 Aug 2018 15:37:51 GMT

data r ;                             
  set s ;                   
  random = rand ("table",0.5,0.5) ;
run ;

Rand table is good for generating integers with known probabilities. The above results in 1 or 2 with probabilities of 0.5 and 0.5.

If you wanted a different distribution such as 60% 1 and 40% 2 then

data r ;                             
  set s ;                   
  random = (rand ("table",0.6,0.4) ;
run ;

You can use any number of probabilities as long as they total to 1 though for values with repeating decimals such as 1/3 using a variable or the calculation in the table options:

random = rand ("table",1/3,1/3,1/3) ;