topic Re: Trunc by 0.5 in SAS Programming

Trunc by 0.5

filippo_kow — Mon, 13 Jan 2025 15:59:42 GMT

Hi guys,

I have a quite trivial problem. I have a number which can have one decimal point and I want to "trunc it down" by 0.5 step. It means: if I have 2.2 I want 2. If I have 2.4 I want 2. If I have 2.6 I want 2.5, like shown in the following code:

data numbers;
    input have $3. want $5.;
    datalines;
2.2 2
2.6 2.5
2.9 2.5
3.1 3
;
run;

Can anyone help me please? 🙂

Thanks in advance!
Filip

Re: Trunc by 0.5

quickbluefish — Mon, 13 Jan 2025 16:12:27 GMT


x=((x-int(x))>=0.5)*0.5+int(x);

Re: Trunc by 0.5

Tom — Mon, 13 Jan 2025 16:15:43 GMT

Very simple.

data numbers;
  input have want ;
  result = int(2*have)/2 ;
  diff = result-want;
datalines;
2.2 2
2.6 2.5
2.9 2.5
3.1 3
;

proc print;
run;

If you really have character variables instead of numbers then first convert the character string into a number using INPUT(). If you want a character result then convert the number to a string using PUT().

Re: Trunc by 0.5

mkeintz — Mon, 13 Jan 2025 18:06:39 GMT

I think your objective can be resolved via the second argument of the ROUND function:

want=round(have,0.5);

If you are starting out with character variable (say with length 5), then

want=round(input(have,5.),0.5);

Re: Trunc by 0.5

filippo_kow — Tue, 14 Jan 2025 10:50:09 GMT

Hi guys,

Thanks a lot for you answers, it helped me a lot 🙂

Best,

Filip