topic Re: How to create dummy variables in SAS Programming

How to create dummy variables

Zakir — Tue, 28 Aug 2018 09:47:59 GMT

Hi Everyone,

I have a trading data set which contains time, bidder, asker, price and volume variable. The data set looks like this:

Data I Have
I want to create dummy variables based on unique bidder. The idea is if a bidder appears in the bidder column, dummy variable should take 0 and if the same bidder appears anywhere in the asking column, dummy variable should take 1. If write the code, it looks:

data want; set have;
if bidder="ByronHal" then dum1=0; if asker="ByronHal" then dum1=1;
if bidder="EdyssaPal" then dum2=0; if asker="EdyssaPal" then dum2=1;
...........

if bidder="ZacharyBra" then dum9=0; if asker="ZacharyBra" then dum9=1;
run;

The problem for this code is manual. I need to look manually who are bidders and type their names. Is there any way to do this by the program!! I mean let the program decide how many unique bidders are there and generate dummies. Finally, can I get sub samples for each bidder from that file. The final sub samples for each bidder should look like this:

Sub Sample for bidder1

Sun Sample1
sub sample for bidder2

Sub Sample2
Let me thank you in advance for helping!!

Zakir

Re: How to create dummy variables

Kurt_Bremser — Tue, 28 Aug 2018 10:03:36 GMT

I'd create formats from the names, set one new variable using that format, and then transpose to the wide format with the multiple dummies.

Please supply example data in a readily usable format (data step with datalines).

Re: How to create dummy variables

s_lassen — Tue, 28 Aug 2018 10:17:56 GMT

You can do it something like this:

data have;
  input bidder $ asker $;
cards;
a b
a c
b a
c d
;run;


proc sql;
  create table brokers as select monotonic() as id,broker
  from(select bidder as broker from have union select asker as broker from have);
  %let n=&sqlobs;
  create index broker on brokers(broker);
quit;

data dummy;
  set have;
  array dummies (*) dum1-dum&n;
  set brokers(rename=(broker=asker)) key=asker/unique;
  dummies(id)=1;
  set brokers(rename=(broker=bidder)) key=bidder/unique;
  dummies(id)=0;
  drop id;
run;

But what are you goint to use that for? It is very bad programming practice to put data (broker IDs) into variable names.

Re: How to create dummy variables

Zakir — Tue, 28 Aug 2018 12:01:50 GMT

Hi s_lassen,

Thank you for your kind help. The first part of the problem is solved. Would you please advise me how to do sub-sampling based on each bidder which will contain observations as shown below:

Sub-sample I want

May I request to provide macro codes so that I can get each bidder's trading detail in one run.

Re: How to create dummy variables

ballardw — Tue, 28 Aug 2018 19:44:25 GMT

And the rule(s) for creating the subsample are what if any?