topic Re: Is there a SAS command to calculate the probability of one event? in SAS Programming

Is there a SAS command to calculate the probability of one event?

Fara_I — Tue, 12 Mar 2019 04:21:23 GMT

I have the following code that simulates the 36 possible outcomes of throwing two six-sided dice, but I wanted to know if there is a SAS command that will tell me that the probability of any one throw is 1/36 or approximately 2.78%? Thank you in advance for any help you can provide me!

Here is the code:

data auto;
do D1= 1 to 6;
do D2= 1 to 6;
X = sum(D1, D2);
output;
end;
end;

Re: Is there a SAS command to calculate the probability of one event?

s_lassen — Tue, 12 Mar 2019 11:09:27 GMT

The short answer is: there is not. If you want the probabilities for each result, try something like this:

data prob;
  array prob(2:12) prob2-prob12;
  do d1=1 to 6;
    do d2=1 to 6;
      prob(d1+d2)+1/36;
      end;
   end;
  drop d1 d2;
run;

But if you just want the probability for each throw, it is 1/(6**2)=1/36. I do not think there is a special function for that.

Re: Is there a SAS command to calculate the probability of one event?

Ksharp — Tue, 12 Mar 2019 12:18:41 GMT

Calling @Rick_SAS

Re: Is there a SAS command to calculate the probability of one event?

ballardw — Tue, 12 Mar 2019 15:42:27 GMT

@Fara_I wrote:

I have the following code that simulates the 36 possible outcomes of throwing two six-sided dice, but I wanted to know if there is a SAS command that will tell me that the probability of any one throw is 1/36 or approximately 2.78%? Thank you in advance for any help you can provide me!

Here is the code:

data auto;
do D1= 1 to 6;
do D2= 1 to 6;
X = sum(D1, D2);
output;
end;
end;

proc freq data=auto;
   table x;
run;

With display, by default, the percent of the distribution points of the X variable. That "Percent" would also be the probability distribution of X, barring rounding error. You can send the output to a data set.

If you want the distribution of each possible die toss then you need to create an ordered pair such as:

data auto;
   do D1= 1 to 6;
      do D2= 1 to 6;
         X = sum(D1, D2);
         y = cats(d1,d2);
         output;
      end;
   end;
run;

proc freq data=auto;
   table x y;
run;

And proc freq again shows the percent, or probability, of each ordered pair.

For any given PERMUTATION of items the probability is basically 1/(n1*n2*n3*…*nx) where each n is the number of possibilities for that position. Simple 6-sided die the N is always 6 so the probability of any given ordered pair is 1/(6^n) for any given number of dice. 6^n is 6 to the nth power.

Combinatorics is somewhat fun, but I'm possibly warped.