topic Spliting a String into 3 observations using an Identifier in SAS Data Management

Spliting a String into 3 observations using an Identifier

shasank — Thu, 12 Oct 2017 19:18:22 GMT

Hi SAS Community, I need you help in the following problem.

I have a dataset that looks like this

NDC	PHARM_CLASSES
21434	GLP-1 Receptor Agonist [EPC],Glucagon-Like Peptide 1 [Chemical/Ingredient],Glucagon-like Peptide-1 (GLP-1) Agonists [MoA]
21445	.
21975	Androgen [EPC],Androgen Receptor Agonists [MoA],Androstanes [Chemical/Ingredient]
21977	Androgen [EPC],Androgen Receptor Agonists [MoA],Androstanes [Chemical/Ingredient]
23004	.
23227	Norepinephrine Reuptake Inhibitor [EPC],Norepinephrine Uptake Inhibitors [MoA]

and I am hoping to get an output like this

NDC	EPC	MoA	Chemical Ingredient
21434	GLP-1 Receptor Agonist	Glucagon-like Peptide-1 (GLP-1) Agonists	Glucagon-Like Peptide 1
21445	.	.	.
21975	Androgen	Androgen Receptor Agonists	Androstanes
21977	Androgen	Androgen Receptor Agonists	Androstanes
23004	.	.	.
23227	Norepinephrine Reuptake Inhibitor	Norepinephrine Uptake Inhibitors	.

I have got help for the same problem previously but, I get a WARNING: 2761 observations omitted due to missing values in the ID variables due to PROC TRANSPOSE. I don't want to loose any observation. Can anyone help me with this problem.

Thank you in advance

 
data middle;
  set NDCdata(Keep= PHARM_CLASSES  NDC);
  length term $150 tag $20 ;
  do i=1 by 1 until (term=' ');
    term=strip(scan(PHARM_CLASSES,i,','));
    tag=scan(term,2,'[]');
    if term ne ' ' then output;
  end;
run;

proc sort data=middle ;
  by NDC tag ;
run;

data middle2 ;
  set middle ;
  by NDC tag ;
  rep+1;
  if first.tag then rep=1;
run;

proc transpose data=middle2 out=want(drop=_name_) ;
  by  NDC;
  id tag rep ;
  var term ;
run;

data cc;
set want (Keep = NDC Chemical_Ingredient1 EPC1 MoA1);
run;

proc sort data = b out = bsort Tagsort nodupkey;
by NDC;
run;

proc sort data = cc out = ccsort Tagsort nodupkey;
by NDC;
run;


 data dd ; 
   merge bsort ccsort ; 
   by NDC ; 
   where NDC ^= '.' ; 
   drop productID;
 run

Re: Spliting a String into 3 observations using an Identifier

Astounding — Thu, 12 Oct 2017 19:49:50 GMT

It is possible that the original code you are working with is overkill and could be simplified considerably. The right route depends on how well you know what is in your data. For a single observation, is it possible that there is more than one MoA compound listed? (That question applies to EPC and Chemical/Ingredient as well.) If not, extreme simplifications are in order.

Re: Spliting a String into 3 observations using an Identifier

shasank — Thu, 12 Oct 2017 20:01:03 GMT

Hi Astounding,
Yes, There are more than 1 occurrences, but I need only the 1st occurrence i:e I Need only the 1st MoA even if 2 MoA or greater are present.
Will this simplify the problem??

Re: Spliting a String into 3 observations using an Identifier

Astounding — Thu, 12 Oct 2017 20:15:56 GMT

Sure, that's enough to simplify. This is untested, so might need minor tweaking:

data want;

set have;

length EPC MoA Chemical_Ingredient term $ 150 tag $ 20;

do j=1 by 1 until (term=' ');

term = scan(PHARM_CLASSES, j, ',');

if term > ' ' then do;

tag = scan(term, 2, '][');

if upcase(tag) = 'MOA' and MoA=' ' then MoA = scan(term, 1, '][');

else if upcase(tag) = 'EPC' and EPC=' ' then EPC = scan(term, 1, '][');

else if upcase(tag) = 'CHEMICAL/INGREDIENT' and Chemical_Ingredient = ' ' then Chemical_Ingredient = scan(term, 1, '][');

end;

drop j term tag PHARM_CLASSES;

run;

You might want to keep PHARM_CLASSSES at first, until you are confident that the results are correct.

Re: Spliting a String into 3 observations using an Identifier

shasank — Thu, 12 Oct 2017 20:28:06 GMT

Worked like a charm.

Thanks a lot.

Re: Spliting a String into 3 observations using an Identifier

mkeintz — Thu, 12 Oct 2017 21:11:09 GMT

This is a late response, but is a little easier to generalize to several/dozens of variables.

data have;
  input NDC PHARM_CLASSES :$&200. ;
datalines;
21434 GLP-1 Receptor Agonist [EPC],Glucagon-Like Peptide 1 [Chemical/Ingredient],Glucagon-like Peptide-1 (GLP-1) Agonists [MoA] 
21445 . 
21975 Androgen [EPC],Androgen Receptor Agonists [MoA],Androstanes [Chemical/Ingredient] 
21977 Androgen [EPC],Androgen Receptor Agonists [MoA],Androstanes [Chemical/Ingredient] 
23004 . 
23227 Norepinephrine Reuptake Inhibitor [EPC],Norepinephrine Uptake Inhibitors [MoA] 
run;
data want (drop=_:);
  set have;
  array vars{3} $60 epc chemical_ingredient moa;

  length _tag_list $40 ;
  retain _tag_list '[EPC] [Chemical/Ingredient] [MoA]';
 
  do _P=1  by 1 while(scan(pharm_classes,_P,',')^='');       
     _value_tag_pair=scan(pharm_classes,_P,',');             
	 _v=findw(_tag_list,trim(scan(_value_tag_pair,-1,' ')),' ','e');    
	 if _v^=0 then vars{_v}=scan(_value_tag_pair,1,'[');               
  end;
run;

This works by searching the tag-in-hand against the tag_list, yielding the position of the current tag in the list. This position (_V) is used to assign a value to the appropriate element in character-array VARS.

Re: Spliting a String into 3 observations using an Identifier

shasank — Thu, 12 Oct 2017 22:02:49 GMT

Thanks alot. This helps.