topic Re: assigning binary values if variable matches in first instance for 'n' times for unsorted data in SAS Programming

assigning binary values if variable matches in first instance for 'n' times for unsorted data

sebster24 — Tue, 30 Aug 2016 08:53:23 GMT

Hello,

I hope you guys are well.

DATA: The data is unsorted and hence I am using hash tables. Sorting this table would be a time-consuming effort. If there is no other option, then I will need to sit down for the gruesome sorting approach.

What I want: I am trying to enumerate a table variable "answer" with binary values (0/1) if variable filter = "Y" for the next 6 observations with the same client. In short if variable filter "Y" then this observation and the next 5 observations for same client should be assigned variable "answer" eq 1, else 0.

I have presented the "have" and "want" data below:


data have;
input client $ dates date9. filter $;
datalines ;
Fg5151 28.Feb.06 N
Fg5151 31.Mar.06 N
Fg5151 30.Apr.06 N
Fg5151 31.May.06 Y
Fg5151 30.Jun.06 N
Fg5151 31.Jul.06 Y
Fg5151 31.Aug.06 N
Fg5151 30.Sep.06 N
Fg5151 31.Oct.06 N
Fg5151 30.Nov.06 N
Fg5151 31.Dec.06 N
Fg5151 01.Jan.07 N
A101 28.Feb.06 N
A101 31.Mar.06 N
A101 30.Apr.06 Y
A101 31.May.06 N
A101 30.Jun.06 N
A101 31.Jul.06 N
ABC123 31.Mar.06 N
;


data want;
input client $ dates date9. filter $ answer 8;
datalines ;
A101 28.Feb.06 N 0
A101 31.Mar.06 N 0
A101 30.Apr.06 Y 1
A101 31.May.06 N 1
A101 30.Jun.06 N 1
A101 31.Jul.06 N 1
ABC123 31.Mar.06 N 0
Fg5151 28.Feb.06 N 0
Fg5151 31.Mar.06 N 0
Fg5151 30.Apr.06 N 0
Fg5151 31.May.06 Y 1
Fg5151 30.Jun.06 N 1
Fg5151 31.Jul.06 Y 1
Fg5151 31.Aug.06 N 1
Fg5151 30.Sep.06 N 1
Fg5151 31.Oct.06 N 1
Fg5151 30.Nov.06 N 1
Fg5151 31.Dec.06 N 1
Fg5151 01.Jan.07 N 0
;

I have compiled the HASH code below - The code works, but variable "answer" provides unsatisfactory results:

data _null_;
	set have end=last;
	retain counter;
	if _n_ = 1 then do;
		length newdate 8 answer 8;
		format newdate ddmmyy10.;
		declare hash hs(ordered: "Y", hashexp: 9);
		hs.defineKey("client","dates");
		hs.defineData("client","dates","filter","answer","newdate");
		hs.defineDone();
	end;
	rc = hs.find();
	if rc ne 0 then do;
		if filter eq "Y" then do;
			counter+0;
			by CLIENT filter notsorted;
			if first.filter then do;
				answer=1;
				newdate=intnx('month',dates,6,"same");
			end;
		end;
		hs.add();
	end;
	else do;
		counter=0;
	end;
	if last eq 1 then do;
	hs.output(dataset: "want");
	end;
run;

Re: assigning binary values if variable matches in first instance for 'n' times for unsorted data

RW9 — Tue, 30 Aug 2016 09:43:06 GMT

Your want dataset does not match the request - you state you do not want to sort the data, but want is sorted?

You could do it using retain:

data want;
  set have;
  retain answer c;
  if _n_=1 or lag(client) ne client then do;
    answer=0;
    c=0;
  end;
  if filter="Y" then do;
    answer=1;
    c=1;
  end;
  else if answer=1 then c=c+1;
  if c > 6 then do;
    answer=0;
    c=0;
  end;
run;

However I would really advise sorting the data as unlike databases, SAS works better on sorted data (i.e. by group processing).

Re: assigning binary values if variable matches in first instance for 'n' times for unsorted data

sebster24 — Tue, 30 Aug 2016 11:57:18 GMT

Hello RW9,

Firstly, thank you for your prompt response.

sorry about the confusion.

I meant to say table "have" is not sorted. The output table "want" will be sorted.

I am unable to run the sort operation on the original dataset as the dataset is really huge. A sort operation would take around 3 hours for each dataset - Hence sorting may possibly not be the best solution.

I have amended the code that i wrote and included your code snippet into my code. Then it works perfectly fine and produces the data.

However, if i move the data around (i.e. unsort the data i have) then i do not get the want table. Code below:


data have;
input client $ dates date9. filter $;
datalines ;
Fg5151 31.Jul.06 Y
Fg5151 31.Aug.06 N
Fg5151 28.Feb.06 N
Fg5151 31.Mar.06 N
Fg5151 30.Apr.06 N
Fg5151 31.May.06 Y
Fg5151 30.Jun.06 N
Fg5151 30.Sep.06 N
Fg5151 31.Oct.06 N
Fg5151 30.Nov.06 N
Fg5151 31.Dec.06 N
Fg5151 01.Jan.07 N
A101 30.Apr.06 Y
A101 28.Feb.06 N
A101 31.Mar.06 N
A101 31.May.06 N
A101 30.Jun.06 N
A101 31.Jul.06 N
ABC123 31.Mar.06 N
;


data have;
format dates ddmmyy10.;
set have;
dates=put(dates,best9.);
run;

data _null_;
	set have end=last;
	if _n_ = 1 then do;
		length newdate 8 answer 8 c 8;
		format newdate ddmmyy10.;
		declare hash hs(ordered: "Y", hashexp: 9);
		hs.defineKey("client","dates");
		hs.defineData("client","dates","filter","answer","c");
		hs.defineDone();
	end;
	rc = hs.find();
	if rc ne 0 then do;
		retain answer c;
		if _n_=1 or lag(client) ne client then do;
			answer=0;
			c=0;
		end;
		if filter="Y" then do;
			answer=1;
			c=1;
		end;
		else if answer=1 then c=c+1;
		if c > 6 then do;
			answer=0;
			c=0;
/*			hs.replace();*/
		end;
		hs.replace();
	end;
	if last eq 1 then do;
hs.output(dataset:
		"not_working");
	end;
run;

Table "not_working" is the output of the operation.

Table "want" is what i am after:


data want;
input client $ dates date9. filter $ answer $;
datalines ;
A101 28.Feb.06 N 0
A101 31.Mar.06 N 0
A101 30.Apr.06 Y 1
A101 31.May.06 N 1
A101 30.Jun.06 N 1
A101 31.Jul.06 N 1
ABC123 31.Mar.06 N 0
Fg5151 28.Feb.06 N 0
Fg5151 31.Mar.06 N 0
Fg5151 30.Apr.06 N 0
Fg5151 31.May.06 Y 1
Fg5151 30.Jun.06 N 1
Fg5151 31.Jul.06 Y 1
Fg5151 31.Aug.06 N 1
Fg5151 30.Sep.06 N 1
Fg5151 31.Oct.06 N 1
Fg5151 30.Nov.06 N 1
Fg5151 31.Dec.06 N 1
Fg5151 01.Jan.07 N 0
;

Many thanks.

regards,

Sebastian

Re: assigning binary values if variable matches in first instance for 'n' times for unsorted data

Ksharp — Tue, 30 Aug 2016 14:01:37 GMT


data have;
input client $ dates : date9. filter $;
n+1;
format dates date9.;
datalines ;
Fg5151 28.Feb.06 N
Fg5151 31.Mar.06 N
Fg5151 30.Apr.06 N
Fg5151 31.May.06 Y
Fg5151 30.Jun.06 N
Fg5151 31.Jul.06 Y
Fg5151 31.Aug.06 N
Fg5151 30.Sep.06 N
Fg5151 31.Oct.06 N
Fg5151 30.Nov.06 N
Fg5151 31.Dec.06 N
Fg5151 01.Jan.07 N
A101 28.Feb.06 N
A101 31.Mar.06 N
A101 30.Apr.06 Y
A101 31.May.06 N
A101 30.Jun.06 N
A101 31.Jul.06 N
ABC123 31.Mar.06 N
;
run;
data key;
 set have(keep=client filter n where=(filter='Y'));
 output;
 do i=1 to 5;
  n=n+1;output;
 end;
 drop i;
run;
data want;
 if _n_=1 then do;
  declare hash h(dataset:'key',hashexp:20);
  h.definekey('client','n');
  h.definedone();
 end;
set have;
if h.check()=0 then answer=1;
 else answer=0;
run;

Re: assigning binary values if variable matches in first instance for 'n' times for unsorted data

sebster24 — Tue, 30 Aug 2016 14:13:04 GMT

Hello Xia Keshan (KSharp),
Instead of picking up next 6 observations, what if I want observations in the next 6 months?
I created a post: https://communities.sas.com/t5/Base-SAS-Programming/sas-enumeration-variable-for-next-6-months/m-p/295164
thank you so much.