topic Re: Macro do loop - skip certain conditions in SAS Programming

Macro do loop - skip certain conditions

hhchenfx — Sat, 25 Feb 2017 21:11:12 GMT

Hi Everyone,

I run a macro like the below and I dont want to run for ,say i=5 and j=3. I dont know the command to skip this and move on to the next itterartion.

Could anyone help me with it?

Thanks so much.

Hhc

%macro comp;
%local i j;
%do i=1 %to 100;
  %do j=1 %to 100;

% IF &I=5 %AND J=3 %THEN "MOVE TO NEXT".

%end;
%end;

%mend;

Re: Macro do loop - skip certain conditions

Reeza — Sat, 25 Feb 2017 21:26:34 GMT

Use an else and skip it otherwise? Make sure you have enough %end, formatting can help with seeing that clearly.

%macro comp;
    %local i j;

    %do i=1 %to 100;

        %do j=1 %to 100;

            %IF &I=5 %AND J=3 %THEN
                %do;
                %end;
            %else
                %do;
                    *rest of statements;
                %end;
        %end;
    %end;
%mend;

Re: Macro do loop - skip certain conditions

LaurieF — Sat, 25 Feb 2017 21:33:10 GMT

First off, you want and not %and!

There's no equivalent of the continue and leave commands within macro code. But you can simulate it by:

%macro comp;
%local i j;
%do i=1 %to 100;
  %do j=1 %to 100;
     %IF &I=5 AND J=3 %THEN 
         %goto continue;
     %lotsOfOtherStuff;
     %continue:
     %end;
%end;

%mend comp;

%comp;

Re: Macro do loop - skip certain conditions

LaurieF — Sat, 25 Feb 2017 21:32:51 GMT

Additionally, if you want to simulate the data step leave:

%macro comp;
%local i j;
%do I=1 %to 100;
  %do j=1 %to 100;
     %IF &I=5 AND J=3 %THEN 
         %goto leave;
     %lotsOfOtherStuff;
     %continue:
     %end;
%leave:
%Lotsmorestuff;
%end;

%mend comp;

%comp;

Re: Macro do loop - skip certain conditions

Kurt_Bremser — Sat, 25 Feb 2017 21:59:02 GMT

Reverse the condition:

%macro comp;
%local i j;
%do i=1 %to 100;
  %do j=1 %to 100;
    %if &i. ne 5 or &j. ne 3 %then %do;
      /* your code */
    %end;
  %end;
%end;
%mend;

Re: Macro do loop - skip certain conditions

Yavuz — Sat, 25 Feb 2017 22:06:14 GMT

@Kurt_Bremser Sorry but as i understand in your code, if then logic have to be "and" instead of "or"

Re: Macro do loop - skip certain conditions

Kurt_Bremser — Sat, 25 Feb 2017 22:19:06 GMT

@Yavuz wrote:
@Kurt_Bremser Sorry but as i understand in your code, if then logic have to be "and" instead of "or"

The OP wants that his %do loop body does not execute when i = 5 and j = 3,

Boolean math: not (x and y) = (not x) or (not y)

So I execute the loop body when i is not 5 or j is not 3.

Re: Macro do loop - skip certain conditions

Yavuz — Sat, 25 Feb 2017 22:22:57 GMT

Thanks a lot Sir,

Re: Macro do loop - skip certain conditions

LaurieF — Sat, 25 Feb 2017 22:32:28 GMT

De Morgan's laws:

The negation of a conjunction is the disjunction of the negations; and the negation of a disjunction is the conjunction of the negations

or:

The nots of the ands is the ors of the nots; the nots of the ors is the ands of the nots.

I found that in an old SAS manual!

Re: Macro do loop - skip certain conditions

hhchenfx — Sun, 26 Feb 2017 04:06:43 GMT

Really thank you all very much!

HHC