CODEWITHSUNDEEP
sasroundingprecision
Giacomo Gaglione
Giacomo Gaglione

Reputation: 21

SAS rounding half down 2 decimals

Cheers!

Long story short I'm trying to deal with SAS rounding function and floating point precision.

Basically, I need to round half down to two decimals so, i.e. 1.235 should round to 1.23 and not 1.24

Here follow an example:

number desired_output
1.230 1.23
1.235 1.23
1.2355 1.24
1.2305 1.23
1.231 1.23
1.236 1.24

I have tried many ways without success (i.e. several combinations of round(), ceil(), floor() and rounde() functions) but, to replicate the exercise, here below some tests:

data test;
input number desired_output;
datalines;
1.230 1.23
1.235 1.23
1.2355 1.24
1.2305 1.23
1.231 1.23
1.236 1.24
; 
run;

data test;
set test;
round_01=round(number,.01);
round_ceil_01=ceil(round_01*100)/100;
round_floor_01=floor(round_01*100)/100;
round_even=rounde(number,.01);
less_half_rounding_factor=round(number-0.0005,.01);
run;

Thank you in advance!

Upvotes: 0

Views: 768

Answers (2)

Tom
Tom

Reputation: 51611

How about:

round(number,0.01) - 0.01*(mod(number,0.01)=0.005)

Remove 0.01 when the next digit is exactly 5.

Test: Let's generate numbers to 5 decimal places and keep only those where the ROUND() function differs from the "round_down" logic above.

data test;
  do integer=1 to 100000 ;
     number=integer/100000 ;
     round=round(number,0.01);
     round_down = round(number,0.01) - 0.01*(mod(number,0.01)=0.005);
     if round ne round_down then output;
  end;
run;

Now let's check if any of them are those that are different are not those where the 3 least significant decimal places are 500, that is exactly X.XX500 .

data test2;
  set test;
  where 500 ne mod(integer,1000) ;
run;

So there were 100 cases where ROUND and ROUND_DOWN differed and they were all the cases where the value had a 5 in the thousands place and zeros after that.

Upvotes: 1

Manojs
Manojs

Reputation: 21

Hope this is what you are looking for

data test;
   set test;
   value = input(put(number,4.2)best.);
run;

Upvotes: 0

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