scan a numeric macro variable

[Xiaoningdemao]

Dear All,

I have code like this:

%let coef = -177 1 -27 -34 -26 -27 -31 -25 -54 -28 -28 -25 -36 -36 7 8 11 50 -9 10 27;

data data;

set data;

score= %scan(&coef,1)*col1 + %scan(&coef,2)*col2 + %scan(&coef,3)*col3;

run;

I want to calc score= -117*col1 + 1*col2 + (-27)*col3;

but i realize that %scan ignored the negative signs, so what i actually got is score= 117*col1 + 1*col2 + (27)*col3.

Can anyone help me resolve this?

Thank you!!

Best wishes.

[Reeza]

A better method, use a temporary array to store the elements and then a loop. 

You have not specified a separator for your terms in the SCAN function. Specify the delimiter/separator. When you create the macro variable list you can specify the delimiter of choice. 

Also, is there a reason for using %scan instead of scan?

[Astounding]

To elaborate on one point within Reeza's answer, %SCAN lets you specify blanks only as delimiters in this fashion:

%scan(&coef,1,%str( ))

Occasionally, you will see a version that is wrong, but usually works properly:

%scan(&coef,1, ' ')

While this does treat blanks as delimiters, it also treats quotes as delimiters.  Usually that doesn't cause any harm, but that probably was not the intention of the programmer.