CODEWITHSUNDEEP
sas
Kavitha
Kavitha

Reputation: 371

Macro Do loop until in sas

I want to find the relationship of O & H or H & O in E1-E6. THEN the output is R6=S6-S5 else R6=S6-S4, else R6=S6-S3 else R6=S6-S2 until we find the relationship, else 0;It should repeat the same way for R5=S5-S4 else R5=S5-S3, else R5=S5-S2 else R5=S5-S1 

SL  E1  E2  E3  E4  E5  E6  S1  S2  S3  S4  S5  S6
1   O   H                   1   4               
2   R   H   O   H           1   6   4   8       
3   O   O   H   O   O   H   2   4   6   7   9   8
4   H   O   R   H   O   H   4   5   4   5   8   7
5   O   O   O   H   H   O   3   5   6   7   7   5
6   O   O   H               2   4   7           
7   H   R   H   O           3   5   6   9       
8   O   H   H   R   O   H   6   7   8   8   6   9
9   O   R   H   H   R       4   7   8   9       
10  R   H   R   O   H       5   8   4   8   9

Typo mistake, Edited. If E6=E5 as OH or HO relation then R6=S6-S5 else S6-S4. To find untill relationship then E5=E4 as OH or HO relation then R5=S5-S4 else S5-S3...,. If HHRO then substract O of S column with next of H column of S, Then there is no need of doing for another H. 

Example output edited

   SL   R2  R3  R4  R5  R6
1   3               
2       -2  4       
3       2       3   -1
4   1       1   3   -1
5           1       -2
6       3           
7           3       
8   1           -2  3
9               5   
10          0   1

Upvotes: 2

Views: 145

Answers (1)

Joe
Joe

Reputation: 63424

Whatever the precise rules are, you don't want to use a macro for this. You want to use a pair of arrays.

data have;
infile datalines missover;
input
SL  E1  $ E2 $  E3 $ E4 $ E5  $ E6 $ S1  S2  S3  S4  S5  S6
;
datalines;
1   O   H   X   X   X   X   1   4               
2   R   H   O   H   X   X   1   6   4   8       
3   O   O   H   O   O   H   2   4   6   7   9   8
4   H   O   R   H   O   H   4   5   4   5   8   7
5   O   O   O   H   H   O   3   5   6   7   7   5
6   O   O   H   X   X   X   2   4   7           
7   H   R   H   O   X   X   3   5   6   9       
8   O   H   H   R   O   H   6   7   8   8   6   9
9   O   R   H   H   R   X   4   7   8   9       
10  R   H   R   O   H   X   5   8   4   8   9   
;;;;
run;

data want;
set have;
array e e1-e6;
array s s1-s6;
array r r2-r6;
matchfound=0;
do _t = dim(s) to 2 by -1;
  do _u = _t-1 to 1 by -1 until (matchfound); *iterate over each lower value of e[];
    *put _n_= e[_t]= e[_u]= _t= _u=;  *uncomment for debugging;
    if cats(e[_t],e[_u]) in ('HO','OH') then do; *if OH or HO;
      matchfound=1;  *set match found so we leave the inner loop;
      r[_t-1] = s[_t] - s[_u]; *calculate R;
    end;
  end;
  if _u >= 1 then _t = _u+1;   *u+1 because it is decremented one time too many automatically;
  else if matchfound=1 then leave;  *if _u =0 and matchfound=1 then we matched the final (u=1);
  matchfound=0; *reset for next lower check;
end;
run;

That probably needs tweaking but should roughly give you the structure to work from.

Upvotes: 1

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