topic Re: Running average score variable based on data getting error messages in SAS Programming

Running average score variable based on data getting error messages

MadQuidd — Thu, 28 Jan 2016 18:19:39 GMT

Working on an assignment and i keep getting an error message.

data scores3;
infile datalines delimiter= '/' dsd;

input StudentID $ Quiz1 Quiz2 Quiz3 Quiz4 Midterm Project Final;

CourseAvg = .1Quiz1 + .1Quiz2 + .1Quiz3 + .1Quiz4 + .2midterm + .2project + .2final;
datalines;
JK/89/100/88/91/100/87/87
DS/100/95/97/69/100/88/85
SR/100/84/98/69/0/./89
RL/99/0/94/0/100/77/55
MZ/100/100/92/97/100/100/98
BB/88/./80/52/100/78/76
AC/100/100/100/98/100/100/98
;
run;

proc print data=scores3;
var StudentID CourseAvg;
run;

the above code keeps coming back with an error message and I dont understand what the error in my code is.

61 CourseAvg = .1Quiz1 + .1Quiz2 + .1Quiz3 + .1Quiz4 + .2midterm + .2project + .2final;

_____ _____ _____ _____ _______

22 22 22 22 22

61 CourseAvg = .1Quiz1 + .1Quiz2 + .1Quiz3 + .1Quiz4 + .2midterm + .2project + .2final;

_______

ERROR 22-322: Syntax error, expecting one of the following: !, !!, &, *, **, +, -, /, ;, <, <=, <>, =, >, ><, >=, AND, EQ, GE, GT,

LE, LT, MAX, MIN, NE, NG, NL, OR, ^=, |, ||, ~=.

61 CourseAvg = .1Quiz1 + .1Quiz2 + .1Quiz3 + .1Quiz4 + .2midterm + .2project + .2final;

_____

ERROR 22-322: Syntax error, expecting one of the following: !, !!, &, *, **, +, -, /, <, <=, <>, =, >, ><, >=, AND, EQ, GE, GT, IN,

LE, LT, MAX, MIN, NE, NG, NL, NOTIN, OR, ^=, |, ||, ~=.

62 datalines;

NOTE: The SAS System stopped processing this step because of errors.

WARNING: The data set WORK.SCORES3 may be incomplete. When this step was stopped there were 0 observations and 9 variables.

WARNING: Data set WORK.SCORES3 was not replaced because this step was stopped.

NOTE: DATA statement used (Total process time):

real time 0.08 seconds

cpu time 0.07 seconds

these are the warning and error messages recieved after inputing the code.

I really dont understand the error in my code. if someone could help that would be greatl appreciated.

Re: Running average score variable based on data getting error messages

mohamed_zaki — Thu, 28 Jan 2016 18:26:38 GMT

@MadQuidd wrote:

CourseAvg = .1Quiz1 + .1Quiz2 + .1Quiz3 + .1Quiz4 + .2midterm + .2project + .2final;

You have two problem in this statment

- Where is the multiplication sign between numbers

- As you have Missing values you better use the SUM() function as it add missing. Not like the +

CourseAvg = sum(.1*Quiz1 , .1*Quiz2 ,.1*Quiz3 , .1*Quiz4 , .2*midterm , .2*project , .2*final);

Re: Running average score variable based on data getting error messages

RyanSimmons — Thu, 28 Jan 2016 18:36:36 GMT

To build on what mohamed said, with this line:

CourseAvg = .1Quiz1 + .1Quiz2 + .1Quiz3 + .1Quiz4 + .2midterm + .2project + .2final;

You are telling SAS to look for a variable called ".1Quiz1", a variable called ".1Quiz2", etc. These are not valid variable names in SAS (which must begin with an English letter or underscore). You need to tell SAS that you are applying a mathematical operation to the variable Quiz1, namely that you want to multiply it by 0.1 (and so on).

Re: Running average score variable based on data getting error messages

mohamed_zaki — Thu, 28 Jan 2016 19:01:55 GMT

Kindly, if you got answers to your questions. Close the thread, by choosing one of the replies as "Accepted Answer".

Re: Running average score variable based on data getting error messages

FreelanceReinh — Fri, 29 Jan 2016 10:21:29 GMT

One more remark (although the thread has been "closed" already ...):

If variable CourseAvg may be used for further processing (e.g. "if CourseAvg>30 then ...") I would strongly recommend to round it to a suitable number of decimals in order to avoid (!) rounding errors (due to numeric representation issues).

Simplified example:

data test;
input id quiz1-quiz3;
cards;
1 35 31 29
2 50 20 30
3 82 53 16
;

data eval;
set test;
avg=sum(.1*Quiz1, .2*Quiz2, .7*Quiz3); /* Risky! No rounding! */
length result $10;
     if avg>30 then result='Pass';
else if avg<30 then result='Fail';
else if avg=30 then result='Borderline';
run;

proc print data=eval noobs;
format avg best32.;
run;

Output:

id    quiz1    quiz2    quiz3                                 avg    result

 1      35       31       29                                   30    Fail
 2      50       20       30                                   30    Borderline
 3      82       53       16                                   30    Pass

As you can see, the three fictitious students are assigned three different results. However, their AVG scores should be exactly equal to 30 in all three cases (simple calculation, e.g. 8.2+10.6+11.2=30 for ID=3) and, indeed, this is what PROC PRINT shows, even with a very long display format such as BEST32..

The RESULT values of students 1 and 3 are incorrect due to tiny rounding errors from the calculation of AVG, which lead to slight deviations from the mathematically correct results (AVG=30): For the computer, ID 1 has AVG=29.999999999999996447... (hence <30) and ID 3 has AVG=30.000000000000003552... (hence >30).

This severe issue (student 1 could file a lawsuit!) could be avoided easily by defining

avg=round(sum(.1*Quiz1, .2*Quiz2, .7*Quiz3), 1e-9);

The small rounding unit (one billionth) is sufficient to flatten the rounding errors (of size 3.55E-15) and would not distort the results either, even if Quiz1-Quiz3 were not integers, but had, say, three decimals.