topic how to get randomization numbers in SAS Programming

how to get randomization numbers

thanikondharish — Wed, 22 Aug 2018 13:52:35 GMT

data main ;
input subid $ condition $ ;
cards ;
101 normal
101 abnormal
102 normal
102 abnormal
103 normal
103 abnormal
;

how to assign type variable

i want to data like see below

subid	condition	type
101	normal	0
101	abnormal	1
102	normal	1
102	abnormal	0
103	normal	0
103	abnormal	1

Re: how to get randomization numbers

PaigeMiller — Wed, 22 Aug 2018 13:54:24 GMT

Please explain the process that assigns a 0 or 1 to type.

Re: how to get randomization numbers

RW9 — Wed, 22 Aug 2018 13:54:35 GMT

Please post full information, how is the 0 or 1 assigned? Maybe:

x=rand('UNIFORM');

From the manual:

http://support.sas.com/documentation/cdl/en/lrdict/64316/HTML/default/viewer.htm#a001466748.htm

Re: how to get randomization numbers

thanikondharish — Wed, 22 Aug 2018 13:56:16 GMT

subjects have type numbers like 0 means subject is not in that condition ,
1 means subject present in that condition

Re: how to get randomization numbers

PeterClemmensen — Wed, 22 Aug 2018 13:57:47 GMT

Is type simply a random 0/1 variable?

If so then do

data want;
   set main;
   a=rand('Integer', 0, 1);
run;

Re: how to get randomization numbers

VDD — Wed, 22 Aug 2018 14:13:20 GMT

is 0 and 1 always assigned to normal = 0 and abnormal = 1?

having a full understanding of what you have and what you want, and maybe the why helps others understand without having to solve the implied assumptions.

Re: how to get randomization numbers

PaigeMiller — Wed, 22 Aug 2018 14:21:59 GMT

@thanikondharish wrote:
subjects have type numbers like 0 means subject is not in that condition ,
1 means subject present in that condition

But this explains nothing. The question is not what does 0 or 1 mean. The question is: How do we assign the 0 or the 1?

Re: how to get randomization numbers

PaigeMiller — Wed, 22 Aug 2018 14:22:57 GMT

@VDD wrote:

is 0 and 1 always assigned to normal = 0 and abnormal = 1?

The original example did not follow this rule.

having a full understanding of what you have and what you want, and maybe the why helps others understand without having to solve the implied assumptions.

Yes, I agree completely, there's no way to answer the question without this explanation.

Re: how to get randomization numbers

ballardw — Wed, 22 Aug 2018 14:24:25 GMT

One way to assign a random value of 0 or 1.

data want;
 set have;
 type= rand('table',.5, .5) -1;
run;

The .5 are the probabilities of selection. If you want/need other than 50/50 split adjust the values but keep a total of 1.

Re: how to get randomization numbers

Reeza — Wed, 22 Aug 2018 14:55:36 GMT

RAND() function with Bernoulli option and you can specify the probability of a 0 or 1.

@thanikondharish wrote:

data main ;
input subid $ condition $ ;
cards ;
101 normal
101 abnormal
102 normal
102 abnormal
103 normal
103 abnormal
;

how to assign type variable

i want to data like see below

subid

condition

type

101

normal

0

101

abnormal

1

102

normal

1

102

abnormal

0

103

normal

0

103

abnormal

1

Re: how to get randomization numbers

Ksharp — Wed, 22 Aug 2018 15:54:12 GMT

data main ;
input subid $ condition $ ;
array x{0:1} _temporary_ ;
call streaminit(12345678);
i=mod(_n_,2);
if i=1 then do;
    if rand('bern',0.5)=1 then do;x{0}=1;x{1}=0;end;
	 else do;x{0}=0;x{1}=1;end;
end;
flag=x{i};
drop i ;
cards ;
101 normal
101 abnormal
102 normal
102 abnormal
103 normal
103 abnormal
;