topic Re: Nested Do Loop (Only want to accumulate within 1 loop) in SAS Programming

Nested Do Loop (Only want to accumulate within 1 loop)

Statistics91 — Sun, 29 Jun 2014 04:21:53 GMT

Hi all,

I currently have this program which is supposed to simulate a gambling strategy (educational purposes; this is not a winning strategy by any means). My program is not quite working because when the 2nd iteration of k begins, the InHand variable continues to accumulate from the final value of when k = 1. Essentially, I need the InHand to go back to starting at 0 when a new iteration of k begins. Basically, I just want to repeat everything in the 'i' loop 10,000 times

Does anyone have an idea of a modification I can make to fix this?

data gamble;

do k = 1 to 10000;

do i = 1 to 100000 until (Strategy = "STOP");

Win = RAND('BINOMIAL',0.476,1);

if Win = 1 then Payoff = 5;

else if Win = 0 then Payoff = -5;

InHand + Payoff;

if InHand >= 45 then Strategy = "STOP";

else if InHand <= -50 then Strategy = "STOP";

else Strategy = "CONTINUE";

if InHand = 45 then Result = "WIN ";

else Result = "LOSS";

end;

output;

end;

run;

Thank you in advance!

Re: Nested Do Loop (Only want to accumulate within 1 loop)

slchen — Sun, 29 Jun 2014 15:43:46 GMT

This is what you need?

data gamble;

do k = 1 to 10000;

do i = 1 to 100000 until (Strategy = "STOP");

Win = RAND('BINOMIAL',0.476,1);

if Win = 1 then Payoff = 5;

else if Win = 0 then Payoff = -5;

InHand + Payoff;

if InHand >=45 or inHand<=-50 then Strategy = "STOP";

else Strategy = "CONTINUE";

if InHand = 45 then Result = "WIN ";

else Result = "LOSS";

end;

output;

call missing(Inhand);

end;

run;

Re: Nested Do Loop (Only want to accumulate within 1 loop)

PGStats — Sun, 29 Jun 2014 15:53:08 GMT

All you need is the statement InHand = 0; after do k = 1 to 10000;

I also suggest calling STREAMINIT as the first statement of the datastep to get reproducible results.

Why two output statements?

You may also consider replacing the BINOMIAL distribution with the BERNOULLI.

Re: Nested Do Loop (Only want to accumulate within 1 loop)

Statistics91 — Mon, 30 Jun 2014 12:24:34 GMT

Thanks a lot to both of you for your help. Both solutions worked perfectly.