topic Re: IF Statement [how to improve your question] in SAS Programming

IF Statement

Miah — Mon, 05 Mar 2018 01:39:47 GMT

I need to create a variable in my data set, indicating how many times each specimen was captured called NumCap. Then I need to alter the AgeGroup variable so that any specimen in the semi-adult group is classified as adult.

Finally I need to print the data set so that only the Sex, AgeGroup, Weight, and NumCap variables are displayed.

PROC IMPORT OUT= work.capture
	DATAFILE= "/folders/myfolders/Capture.txt"
	DBMS=CSV REPLACE;
	DELIMITER='09'x;
	GETNAMES=YES;
RUN; 

PROC PRINT DATA=work.capture;
RUN; 

DATA capture; 
	SET capture; 
	NumCap = 0;
	IF (Cap1 == 'yes') THEN DO; 
	NumCap +1; 
	IF (Cap2 == 'yes') THEN DO; 
	NumCap +1; 
	IF (Cap3 == 'yes') THEN DO; 
	NumCap +1; 
	IF (Cap4 == 'yes') THEN DO; 
	NumCap +1; 
	IF (Cap5 == 'yes') THEN DO; 
	NumCap +1; 
	IF (Cap6 == 'yes') THEN DO; 
	NumCap +1; 
RUN;

DATA capture; 
	SET capture;
	IF (AgeGroup == 'semi-adult') THEN DO;
	AgeGroup = 'Adult';
RUN;

Re: IF Statement [how to improve your question]

Community_Guide — Mon, 05 Mar 2018 01:27:28 GMT

Hello @Miah,

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Re: IF Statement

Reeza — Mon, 05 Mar 2018 01:29:33 GMT

What have you tried so far?

Showing what you've attempted makes it easier to help you.

If you're not sure where to start, PROC MEANS calculates summary statistics and PROC FREQ generates summary counts.

This section has a lot of tutorials and the first two programming e-courses are free.

http://video.sas.com/#category/videos/sas-analytics-u

Re: IF Statement

Miah — Mon, 05 Mar 2018 01:41:13 GMT

PROC IMPORT OUT= work.capture
	DATAFILE= "/folders/myfolders/Capture.txt"
	DBMS=CSV REPLACE;
	DELIMITER='09'x;
	GETNAMES=YES;
RUN; 

PROC PRINT DATA=work.capture;
RUN; 

DATA capture; 
	SET capture; 
	NumCap = 0;
	IF (Cap1 == 'yes') THEN DO; 
	NumCap +1; 
	IF (Cap2 == 'yes') THEN DO; 
	NumCap +1; 
	IF (Cap3 == 'yes') THEN DO; 
	NumCap +1; 
	IF (Cap4 == 'yes') THEN DO; 
	NumCap +1; 
	IF (Cap5 == 'yes') THEN DO; 
	NumCap +1; 
	IF (Cap6 == 'yes') THEN DO; 
	NumCap +1; 
RUN;

DATA capture; 
	SET capture;
	IF (AgeGroup == 'semi-adult') THEN DO;
	AgeGroup = 'Adult';
RUN;

Re: IF Statement

Reeza — Mon, 05 Mar 2018 02:24:20 GMT

DATA capture; 
	SET capture;

Coding like that makes it really hard to figure out where you made a mistake, make sure each DATA creates a unique data set instead.

SAS does not use a double == to test equality, a single equal sign is necessary. How does this code not work or meet your expectations? What are you expecting as output?

If you have an THEN DO block, it needs an END.

	IF (AgeGroup == 'semi-adult') THEN DO;
	AgeGroup = 'Adult';
        END;

Re: IF Statement

Astounding — Mon, 05 Mar 2018 02:28:49 GMT

A few changes to the basic syntax will do the trick.

First, if you want to do something, just do it. You don't have to say THEN DO

Second, you only need one equal sign to assign a value.

The result:

data want;

set capture;

NumCap = 0;

if Cap1='yes' then NumCap + 1;

if Cap2='yes' then NumCap + 1;

if Cap3='yes' then Numcap + 1;

if Cap4='yes' then NumCap + 1;

if Cap5='yes' then NumCap + 1;

if Cap6='yes' then NumCap + 1;

if AgeGroup = 'semi-adult' then AgeGroup = 'Adult';

run;

There are ways to shorten the amount of code, using an array to hold Cap1 through Cap6. I omitted that intentionally, since it is more complex and you are still working on some more basic statements. Just in case it proves useful, these statements could replace 6 IF/THEN statements:

array cap {6};

do k=1 to 6;

if cap{k} = 'yes' then NumCap + 1;

end;

drop k;

Re: IF Statement

Shmuel — Mon, 05 Mar 2018 02:34:56 GMT

Pay attention to sas syntax:

1) DO; statement is used to do one or more statements, each ending by a semicolon (;).

You have to enclose the DO; by END; statement as in:

do;
     <statement 1>;
     <statement 2>;
     ....
end;

2) When you have just one statement to do you don't need a DO; statement.

You can use a more simple syntax like:

if <condition> then <statement>;

3) You can eclose the two missions into one data step.

4) Using above syntax, makes your code into:

DATA capture; 
	SET capture; 
	NumCap = 0;
	IF Cap1 = 'yes'  THEN NumCap +1; 
	IF Cap2 = 'yes'  THEN NumCap +1; 
	IF Cap3 = 'yes'  THEN NumCap +1; 
	IF Cap4 = 'yes'  THEN NumCap +1; 
	IF Cap5 = 'yes'  THEN NumCap +1; 
	IF Cap6 = 'yes'  THEN NumCap +1; 

       IF Agegroup = 'semi-adult' then Agegroup = 'Adult';
RUN;

5) Next code is eqivalent to the above:

DATA capture; 
	SET capture; 
	NumCap = 0;
        array cp Cap1-Cap5;
        do i=1 to 5;
            if cp(i) = 'yes' then numcap +1;
        end;

	IF agegroup = 'semi-adult' then agegroup = 'adult';
run;