topic Re: Help with macros in SAS Programming

Help with macros

stellapersis7 — Thu, 31 Aug 2023 19:28:45 GMT

Hi all,

I have trouble understanding macro.

I have the following code to run for a dataset x, I want a macro code for this to run in x,y, and z data sets.

Can anyone please help me with this?

Here is the code:

data ci;
set CI16;
array d(25) ICD_DX_CD_1 - ICD_DX_CD_25;
DMCAT=0;
do I = 1 to 25;
if d(i) = SUBSTR(D{I},1,3)= 'E08' OR SUBSTR(D{I},1,3) = 'E09' OR SUBSTR(D{I},1,3)= 'E10' OR SUBSTR(D{I},1,3)= 'E11' OR SUBSTR(D{I},1,3)= 'E13'

then DMCAT=1;
end;
run;

Thanks a lot

Re: Help with macros

PaigeMiller — Thu, 31 Aug 2023 19:32:23 GMT

If I am understanding you properly

%macro dothis(dataset=);
data ci;
set &dataset;
array d(25) ICD_DX_CD_1 - ICD_DX_CD_25;
DMCAT=0;
do I = 1 to 25;
if d(i) = SUBSTR(D{I},1,3)= 'E08' OR SUBSTR(D{I},1,3) = 'E09' OR SUBSTR(D{I},1,3)= 'E10' OR SUBSTR(D{I},1,3)= 'E11' OR SUBSTR(D{I},1,3)= 'E13'

then DMCAT=1;
end;
run;
%mend;

%dothis(dataset=x)
%dothis(dataset=y)
%dothis(dataset=z)

Re: Help with macros

sbxkoenk — Thu, 31 Aug 2023 19:37:34 GMT

%MACRO HelpWithMacros(inds=,outds=);
 data &outds.;
  set &inds.;
/* put the body of the datastep here */
 run;
%MEND HelpWithMacros;

options mprint symbolgen mlogic;
%HelpWithMacros(inds=work.X,outds=work.X_out);
%HelpWithMacros(inds=work.Y,outds=work.Y_out);
%HelpWithMacros(inds=work.Z,outds=work.Z_out);
/* end of program */

BR, Koen

Re: Help with macros

Astounding — Thu, 31 Aug 2023 20:43:58 GMT

To encapsulate this program in a macro, suitable for 3 data sets, you need to overcome a couple of problems.

First, the output data set name is ci. That's fine when you have one data set to process. But if you process three data sets, each run replaces ci with a different output. You will need 3 data set names, not 1.

Second, the code itself could use a little bit if cleaning up. In particular:

SUBSTR is inefficient
Continuing to search all 25 variables is inefficient once you already have a single match that sets DMCAT to 1.

Try it this way:

%macro set_dmcat (dsn);
   data ci_&dsn;
      set &dsn;
      array icd_dx_cd_ {25};  /* autoatically uses the array name plus a numeric suffix */
      dmcat=0;
      do i=1 to 25  until (dmcat=1);
         if icd_dx_cd_{i} in: ('E08', 'E09', 'E10', 'E11', 'E13') then dmcat=1;
      end;
run;
%mend set_dmcat;

%set_dmcat (x)
%set_dmcat (y)
%set_dmcat (z)

Using =: compares whether two strings are equal, but makes the comparison using the number of characters in the shorter string. That lets you eliminate SUBSTR when you want to examine the beginning of a string.

Adding the UNTIL condition lets you stop examining the rest of the diagnosis codes once a match has been found.

Re: Help with macros

stellapersis7 — Mon, 04 Sep 2023 14:36:47 GMT

Hi sbxkoenk

my new code for 3 datasets was :

%MACRO HW2_DX(inds=,outds=);

data &outds.;

set &inds.;

array d(26) PRMRY_DX_CD ICD_DX_CD_1 - ICD_DX_CD_25;

DMCAT=0;

%do I = 1 %to 26;

if d(i) = SUBSTR(D{I},1,3)= 'E08' OR SUBSTR(D{I},1,3) = 'E09' OR SUBSTR(D{I},1,3)= 'E10' OR SUBSTR(D{I},1,3)= 'E11' OR SUBSTR(D{I},1,3)= 'E13'

then DMCAT=1;

%end;

%MEND HW2_DX;

options mprint symbolgen mlogic;

%HW2_DX(inds=hw2j.syhdr_commercial_inpatient_2016,outds=hw2_1);

%HW2_DX(inds=hw2j.syhdr_commercial_outpatient_2016,outds=hw2_2);

%HW2_DX(inds=hw2j.syhdr_medicaid_inpatient_2016,outds=hw2_3);

This does not work and gives an error of "variable I is uninitialized"

need some help!

Re: Help with macros

sbxkoenk — Mon, 04 Sep 2023 15:14:58 GMT

Hello,

There is NO variable in your dataset with the name "i".
There is only a macro variable with the name "i".
If you want to resolve the macro variable (to get its value), you need to specify &i. .

(the dot after the macro variable name is only needed if "confusion" is possible)

You don't need quotes here (as you deal with a numeric value)

, but in case you need quotes (for a string value) , just remember this :
Macro variables in SAS won't resolve when they are in single quotes, like '&myvar' . They need to be in double quotes, "&myvar" , in order to resolve properly.

BR, Koen

Re: Help with macros

PaigeMiller — Mon, 04 Sep 2023 17:10:34 GMT

%DO works on macro variables, such as &i. DO works on data step variables, such as i.

In your code, use DO instead of %DO (and TO instead of %TO)