I am doing a poker simulation in SAS. So far I have created a deck, shuffled and dealt 5 card hands (no draw), and kept track of pairs, trips, 4 of a kind, and flushes using proc freq. Now I am trying to get SAS to recognize straights. I have assigned numerical values to the card ranks (2=2, J=11, A=14, etc.). My professor suggested using an Array to do this process and showed me a sample code. The first part is the code I am using where I assigned numerical values. The other data steps (data 1, 2, and 3) are the array. Could someone offer suggestions as to how I would use the array with the code I am using?
%let decksize=52;
%let handsize=5;
%let nsims=10000;
%let nhands=5;
data _null_;
ncards=&handsize*&nhands;
call symput("ncards", ncards);
run;
data deck;
call streaminit(&seed);
do suit="C","D","H","S";
do value="2","3","4","5","6","7","8","9","T","J","Q","K","A";
if value="A" then numval=14;
else if value="2" then numval=2;
else if value="3" then numval=3;
else if value="4" then numval=4;
else if value="5" then numval=5;
else if value="6" then numval=6;
else if value="7" then numval=7;
else if value="8" then numval=8;
else if value="9" then numval=9;
else if value="T" then numval=10;
else if value="J" then numval=11;
else if value="Q" then numval=12;
else numval=13;
if suit="C" then suitval=1;
else if suit="D" then suitval=2;
else if suit="H" then suitval=3;
else suitval=4;
order=rand("uniform");
output;
end;
end;
run;
*Array commands shown by professor;
data one;
do i=2 to 6;
if i^=6 then cards=i;
else cards=6;
output;
end;
run;
data two;
set one;
array hand{5} c1-c5;
retain hand;
hand{_n_}=cards;
if _n_=5;
run;
data three;
set two;
straight=1;
array hand{5} c1-c5;
do i= 1 to 4;
if hand{i+1}-hand{i}^=1 then do;
card=i;
straight=0;
leave;
end;
end;
if card=4 then if hand{5}-hand{4}=9 then straight=1;
run;
commands my professor showed me.
I don't know what that last line of "if card=4" is for.
This identifies straights using that approach.
data example; do c1= 2 to 14; do c2= 2 to 14; do c3= 2 to 14; do c4= 2 to 14; do c5= 2 to 14; output; end; end; end; end; end; run; data three; set example; straight=1; array hand{5} c1-c5; call sortn(of hand(*)); do i= 1 to 4; if hand{i+1}-hand{i}^=1 then do; card=i; straight=0; leave; end; end; run;
but for further hands you'll need to do something to keep the suit with the rank.
Hello Ballard,
The last line is accounting for Aces being valued 1 and 14. So the way he wrote it was that whenever there was a sequence: 2-3-4-5-A, it would calculate that last difference as 9 and count it as a straight as well.
Before seeing your reply, I ran a program that did not result in any errors or warnings, yet I am not quite sure it is doing what I intended i.e. identify straights. Here is what I have so far:
%let seed=1210;
%let decksize=52;
%let handsize=5;
%let nsims=10000;
%let nhands=10;
data _null_;
ncards=&handsize*&nhands;
call symput("ncards", ncards);
run;
data deck;
call streaminit(&seed);
do suit="C","D","H","S";
do value="2","3","4","5","6","7","8","9","T","J","Q","K","A";
if value="A" then numval=14;
else if value="2" then numval=2;
else if value="3" then numval=3;
else if value="4" then numval=4;
else if value="5" then numval=5;
else if value="6" then numval=6;
else if value="7" then numval=7;
else if value="8" then numval=8;
else if value="9" then numval=9;
else if value="T" then numval=10;
else if value="J" then numval=11;
else if value="Q" then numval=12;
else numval=13;
if suit="C" then suitval=1;
else if suit="D" then suitval=2;
else if suit="H" then suitval=3;
else suitval=4;
order=rand("uniform");
output;
end;
end;
run;
proc sort data=deck;
by order;
/*proc print data=deck;
run;*/
proc surveyselect data=deck noprint
method=srs
seed=&seed
sampsize=&ncards
rep=&nsims
out=cards;
run;
/*proc print data=cards;
run; */
data hands;
set cards;
hand=ceil(_n_/&handsize);
run;
data three;
set hands;
straight=1;
array draw{&handsize} c1-c&handsize;
do i= 1 to 4;
if draw{i+1}-draw{i}^=1 then do;
card=i;
straight=0;
leave;
end;
end;
if card=4 then if draw{5}-draw{4}=9 then straight=1;
run;
/*proc print data=hands;
run;*/
/*proc print data=three;
run;*/
proc freq data=hands noprint ;
tables value/out=freqval;
by hand;
run;
proc freq data=hands noprint;
tables suit/out=freqsui;
by hand;
run;
proc freq data=three noprint;
tables straight/out=freqstr;
by hand;
run;
data repthree;
set freqstr;
simno=ceil(hand/&nhands);
run;
data rephand;
set freqval;
simno=ceil(hand/&nhands);
/*proc print data=repthree;
run;*/
proc means data=rephand noprint;
var count;
by simno;
output out=maxnum max=kind;
run;
/*proc freq data=maxnum;
tables kind;
run;*/
proc means data=rephand noprint;
var count;
by simno;
output out=win max=winkind;
run;
proc means data=repthree noprint;
var straight;
by simno;
output out=maxstraight max=winstraight;
run;
proc freq data=win;
tables winkind;
run;
data rephandsuit;
set freqsui;
simno=ceil(hands/&nhands);
run;
proc means data=rephandsuit noprint;
var count;
by simno;
output out=win max=winflush;
run;
/*proc print data=rephandsuit;
run;*/
proc freq data=win;
tables winflush;
run;
proc freq data=maxstraight;
tables winstraight;
run;
Quick follow up:
I did not get any error messages but the ouput for straights (and flushes) do not seem right. For instance, it shows that a hand with 5 matching suits (flush) had a frequency of 100% and that hands that were not straights had a frequency of 100%. So I either used the wrong code to track these hands or the output I created using proc freq is incorrect.
I would go about it slighly differently. I only took the following as far as checking for Straights. You can find more ideas for checking the other scenarios in the thread at: https://communities.sas.com/t5/SAS-Procedures/Allocating-Values-to-Poker-Hands/td-p/146459
Here is my suggested approach (Note: You'd have to create four subrankings based on suit and values. Thus a straight flush would actually have a range of 40 subranks to account for the possible range of values and suits. You could set them to have values of 9.01 to 9.40):
%let decksize=52; %let handsize=5; %let nsims=10000; %let nhands=5; /*missing the following*/ %let seed=0; data _null_; ncards=&handsize*&nhands; call symput("ncards", ncards); run; data deck; call streaminit(&seed); length suit $1; do suit='C','D','H','S'; do value=2 to 14; order=rand("uniform"); output; end; end; run; proc sort data=deck; by order; run; data game (drop=value suit order); array handv(&handsize.); array hands(&handsize.) $; do hands=1 to &nhands.; do cards=1 to &handsize.; set deck; handv(cards)=value; hands(cards)=suit; end; call sortc(of hands(*)); call sortn(of handv(*)); /*create ranks based on*/ /*9=Straight Flush*/ /*8=Four of a Kind*/ /*7=Full House*/ /*6=Flush*/ /*5=Straight*/ /*4=Three of a kind*/ /*3=Two pair*/ /*2=Pair*/ /*1=High card*/ /* check for flush */ if hands(1) eq hands(5) then rank=6; /* check for straight or straight flush */ if handv(5)-handv(4) eq 1 and handv(4)-handv(3) eq 1 and handv(3)-handv(2) eq 1 and handv(2)-handv(1) eq 1 then do; if rank eq 6 then rank=9; else rank=5; end; else if handv(5) eq 14 then if handv(4)-handv(3) eq 1 and handv(3)-handv(2) eq 1 and handv(2)-1 eq 1 then do; if rank eq 6 then rank=9; else rank=5; end; /* check for four of a kind */ else if (sum(of handv(*))-handv(1) eq (4*handv(5))) or (sum(of handv(*))-handv(5) eq (4*handv(1))) then rank=8; end; run;
Art, CEO, AnalystFinder.com
Hello Art,
Thank you for your help. I tried running your code and got some error messages. Please excuse me if I forgot to do something that would account for these errors as I am new to SAS.
Here are the errors:
90 data game (drop=value suit order);
91 array handv(&handsize.);
92 array hands(&handsize.) $;
93 do hands=1 to &nhands.;
ERROR: The variable type of hands is invalid in this context.
93 do hands=1 to &nhands.;
_
133
ERROR 133-185: A loop variable cannot be an array name or a character variable; It must be a scalar numeric.
ERROR: Illegal reference to the array hands.
94 do cards=1 to &handsize.;
95 set deck;
96 handv(cards)=value;
97 hands(cards)=suit;
98 end;
99 call sortc(of hands(*));
100 call sortn(of handv(*));
Sorry, that was an error on my part. I posted without testing .. something one should never do! Try the following instead:
%let decksize=52; %let handsize=5; %let nsims=10000; %let nhands=5; /*missing the following*/ %let seed=0; data _null_; ncards=&handsize*&nhands; call symput("ncards", ncards); run; data deck; call streaminit(&seed); length suit $1; do suit='C','D','H','S'; do value=2 to 14; order=rand("uniform"); output; end; end; run; proc sort data=deck; by order; run; data game (drop=value suit order); array handv(&handsize.); array hands(&handsize.) $; /* deal for each player and score their hand */ do hand=1 to &nhands.; do cards=1 to &handsize.; set deck; handv(cards)=value; hands(cards)=suit; end; call sortc(of hands(*)); call sortn(of handv(*)); /*create ranks based on*/ /*9=Straight Flush*/ /*8=Four of a Kind*/ /*7=Full House*/ /*6=Flush*/ /*5=Straight*/ /*4=Three of a kind*/ /*3=Two pair*/ /*2=Pair*/ /*1=High card*/ /* check for flush */ if hands(1) eq hands(5) then rank=6; /* check for straight or straight flush */ if handv(5)-handv(4) eq 1 and handv(4)-handv(3) eq 1 and handv(3)-handv(2) eq 1 and handv(2)-handv(1) eq 1 then do; if rank eq 6 then rank=9; else rank=5; end; else if handv(5) eq 14 then if handv(4)-handv(3) eq 1 and handv(3)-handv(2) eq 1 and handv(2)-1 eq 1 then do; if rank eq 6 then rank=9; else rank=5; end; /* check for four of a kind */ else if (sum(of handv(*))-handv(1) eq (4*handv(5))) or (sum(of handv(*))-handv(5) eq (4*handv(1))) then rank=8; output; end; stop; run;
Art, CEO, AnalystFinder.com
Thank you again Art.
Interestingly, this is the first time I've tried to write a program that ranks poker hands. My code isn't complete .. for one, it doesn't account for 2nd level ties (e.g., 7 7 6 6 5 compared with 7 7 6 6 4).
However, in taking the code as far as I have, I discovered some things that you really ought to consider. Most importantly, ranking must be done using whole numbers .. otherwise you run into numeric precision issues. That is always a risk, with computers, attempting to do comparisons of calculations as if they were done using base 10 math.
Anyhow, here is what I've done so far:
%let decksize=52; %let handsize=5; %let nsims=10000; %let nhands=5; /*missing the following*/ %let seed=0; data _null_; ncards=&handsize*&nhands; call symput("ncards", ncards); run; data deck; call streaminit(&seed); /* set suit a card values*/ /* suits 1=clubs 2=diamonds 3=hearts 4=spades*/ do suit=1 to 4; do value=2 to 14; order=rand("uniform"); output; end; end; run; proc sort data=deck; by order; run; data hands (drop=value suit order hand cards); array handv(&handsize.); array hands(&handsize.); /* deal for each player */ do hand=1 to &nhands.; do cards=1 to &handsize.; set deck; handv(cards)=value; hands(cards)=suit; end; call sortn(of hands(*)); call sortn(of handv(*)); output; end; stop; run; /*For testing purposes only: create test hands dataset data hands; input handv1-handv5 hands1-hands5; cards; 2 3 4 5 14 1 1 1 1 1 10 11 12 13 14 1 1 1 1 1 9 10 11 12 13 4 4 4 4 4 8 10 11 12 13 4 4 4 4 4 7 9 9 9 9 1 1 2 3 4 4 5 6 7 8 1 1 2 3 4 2 3 4 4 4 1 1 2 3 4 5 6 6 6 7 1 2 2 3 4 8 9 9 9 10 10 2 2 3 3 4 5 6 7 7 7 1 2 3 3 4 2 5 5 6 6 2 2 3 3 4 2 3 4 4 5 1 1 1 2 3 9 10 11 12 14 1 2 2 3 4 4 5 6 8 9 1 1 1 2 3 ; */ data game; set hands; array handv(&handsize.) handv1-handv5; array hands(&handsize.) hands1-hands5; /*create ranks based on*/ /*900=Straight Flush*/ /*800=Four of a Kind*/ /*700=Full House*/ /*600=Flush*/ /*500=Straight*/ /*400=Three of a kind*/ /*300=Two pair*/ /*200=Pair*/ /*100=High card*/ rank=0; /* check for flush */ if hands(1) eq hands(5) then rank=600+handv(5); /* check for straight or straight flush */ if (handv(5)-handv(4)) eq 1 and (handv(4)-handv(3)) eq 1 and (handv(3)-handv(2)) eq 1 and (handv(2)-handv(1)) eq 1 then do; if rank gt 600 then rank=900+handv(5); else rank=500+handv(5); end; /* check for an Ace thru 5 straight or straight flush*/ else if handv(5) eq 14 and handv(4) eq 5 and handv(3) eq 4 and handv(2) eq 3 and handv(1) eq 2 then do; if rank gt 600 then rank=900+handv(4); else rank=500+handv(4); end; if rank lt 500 then do; /* check for four of a kind */ if (sum(of handv(*))-handv(1)) eq (4*handv(5)) or (sum(of handv(*))-handv(5)) eq (4*handv(1)) then rank=800+handv(2); /* check for full house */ else if (handv(1) eq handv(2) and handv(3)=handv(5)) or (handv(1)=handv(3) and handv(4)=handv(5)) then rank=700+handv(3); /* check for three of a kind */ else if (sum(of handv(*))-handv(5)-handv(4)) eq (3*handv(1)) or (sum(of handv(*))-handv(1)-handv(5)) eq (3*handv(2)) or (sum(of handv(*))-handv(1)-handv(2)) eq (3*handv(3)) then rank=400+handv(3); /* check for two pairs */ else if (handv(1) eq handv(2) and handv(3) eq handv(4)) or (handv(1) eq handv(2) and handv(4) eq handv(5)) or (handv(2) eq handv(3) and handv(4) eq handv(5)) then rank=300+handv(4); /* check for one pair */ else if (handv(1) eq handv(2)) or (handv(2) eq handv(3)) or (handv(3) eq handv(4)) or (handv(4) eq handv(5)) then do; if handv(1) eq handv(2) then rank=200+handv(2); else if handv(2) eq handv(3) then rank=200+handv(3); else if handv(3) eq handv(4) then rank=200+handv(4); else if handv(4) eq handv(5) then rank=200+handv(5); end; /* check for high card */ else rank=100+handv(4); end; run;
Of course, the above isn't tested for accuracy .. that part is up to you.
Art, CEO, AnalystFinder.com
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