topic Re: Do loop in data step in SAS Enterprise Guide

Do loop in data step

kanivan51 — Wed, 29 Nov 2017 07:46:55 GMT

Hello!

What is wrong with that script?

%LET MIN=1;
%LET MAX=1000000;

;DATA IDS(KEEP=ID);
RETAIN I;
ATTRIB ID FORMAT=12.;
I=1;
MAX=&MAX.;
DO (WHILE ID<MAX);
ID=&MIN.*I;
OUTPUT;
I+1;
END;
RUN;

Re: Do loop in data step

andreas_lds — Wed, 29 Nov 2017 07:58:39 GMT

You code all upcase.
You didn't use the {i} or running-man-icon to post the code.
I don't have a crystal ball showing the log output and/or what you expected.

Re: Do loop in data step

kanivan51 — Wed, 29 Nov 2017 08:18:14 GMT

%LET MIN=1;
%LET MAX=1000000;

;DATA IDS(KEEP=ID);
RETAIN I;
ATTRIB ID FORMAT=12.;
I=1;
MAX=&MAX.;
DO (WHILE ID<MAX);
ID=&MIN.*I;
OUTPUT;
I+1;
END;
RUN;

Re: Do loop in data step

Kurt_Bremser — Wed, 29 Nov 2017 08:57:53 GMT

Maxim 2: Read the log.

You get this:

1         MAX=&MAX.;
32         DO (WHILE ID<MAX);
                     __
                     22
ERROR: Undeclared array referenced: DO.
32         DO (WHILE ID<MAX);
                            _
                            22
ERROR 22-322: Syntax error, expecting one of the following: !, !!, &, (, *, **, +, ',', -, /, <, <=, <>, =, >, ><, >=, AND, EQ, GE, 
              GT, IN, LE, LT, MAX, MIN, NE, NG, NL, NOTIN, OR, [, ^=, {, |, ||, ~=.  

ERROR 22-322: Syntax error, expecting one of the following: +, =.  

32         DO (WHILE ID<MAX);
                            _
                            76
ERROR 76-322: Syntax error, statement will be ignored.

which points to a problem with the way you wrote the do statement.

Maxim 1: Read the documentation.

The documentation for the do while statement reads:

Syntax

DO WHILE (expression);

which means that the opening parenthesis must come after the "while".

Now look at this:

%let min=1;
%let max=1000000;

data ids(keep=id);
attrib id format=12.;
I = 1;
max = &max.;
do while (id < max);
  id = &min. * i;
  output;
  i + 1;
end;
run;

and tell us which code is easier to read and understand?

Follow Maxim 12, and avoid coding in all-uppercase. The 1950's are long past.

BTW I removed the unnecessary retain statement. Read the documentation what it does and when it should be used.

Re: Do loop in data step

RW9 — Wed, 29 Nov 2017 09:19:04 GMT

Not sure what all the while part is for in the first place, it is a simple loop with a by statement:

data ids2;
  attrib id format=12.;
  do id=&min. to &max. by &min.;
    output;
  end;
run;

Re: Do loop in data step

ballardw — Wed, 29 Nov 2017 16:11:16 GMT

Post LOG information into a code box as well. Then we can cut an paste to show corrections or explanations.

Re: Do loop in data step

kanivan51 — Wed, 29 Nov 2017 22:07:26 GMT

Thanks, RW9! Cool solution! I didn't know about BY statement in loop.