Bound my result to [-1,1] in SAS

Question

I am calculating a fraction based on the payments made in four years and I wish to put a cap on my fraction such that it can only be between -1 and 1. Subsequently I'd like to make the following fractions 0 if the cap is maxxed out - an example would be:

data want;
    input payment1 payment2 payment3 payment4 fraction1 fraction2 fraction3;
    datalines;
100 25 25 25 0.25 0.25 0.25
150 50 50 50 0.33 0.33 0.33
50 10 10 10 0.2 0.2 0.2
10 50 60 70 1 0 0
;
run;

I've been looking at the ceiling function with the following code

data want2;
    set want;
    array fraction(3) fraction1 - fraction3;
    array payment(4) payment1 - payment4;

    do i = 2 to 4;
        fraction(i-1) = payment(i)/payment(1);
    end;
run;

data want3;
    set want2;
    array fraction(3) fraction1 - fraction3;
    array fract(3) fract1-fract3;

    do i = 1 to 3;
        fract = ceil (fraction,1); 
    end;
    drop i;
run;

but I am getting this error

ERROR 72-185: The CEIL function call has too many arguments.

So in all i'm looking for a way to calculate the fraction of the payments and then make a ceiling at one, then once the ceiling is hit, the subsequent fractions must be zero (which could be done I suppose by just doing an IF-THEN)

Answer 1

The ceil function is a type of rounding. You need min and max:

do i = 1 to 3;
    fract = min(max(fraction, -1) ,1); 
end;