topic Re: Rounding in SAS Programming

Rounding

RandyStan — Thu, 30 Mar 2017 18:44:26 GMT

I wantto round 6274.5679 to the nearest integer to get 6275
 
Here is what I wrote 

data want ; set have ;
format newvar 6. ;
newvar = Round(oldvar,1);
run;

the error i get is Variable  is oldvar uninitialized.
What mistake am I making.

Randy

Re: Rounding

Astounding — Thu, 30 Mar 2017 18:53:25 GMT

Evidently, "oldvar" is the incorrect spelling. Run a PROC CONTENTS on your incoming data set to find the correct spelling of the variable names.

Re: Rounding

PeterClemmensen — Thu, 30 Mar 2017 18:56:00 GMT

If you want the integer portion of a variable, the INT function is what you are looking for

data have;
   value = 6274.5679;
   round_value = round(value);
   int_value = int(value);

   put round_value;
   put int_value;
run;

Re: Rounding

rogerjdeangelis — Thu, 30 Mar 2017 19:01:21 GMT

 data _null_;

  x=6274.4999;
  put x hex16.;

  /* here is the problem non-terminating mantissa
     cannot represent the number exactly - you have lost already.
     
  6274.4999
  40B8827FF9724745

  like 1/3 in decimal (never is exact)
   0.3333333333333
  */

  x=62744999;
  put x hex16.;

  /* got it exactly
  62744999
  418DEB4D38000000
  */

  x=6274.5;
  put x hex16.;

  /* got it exactly (when mantissa is a power of 2**(-n))
  6274.5
  40B8828000000000
  */

  /* possible solution;
   summing in the integer domain is exact (given no overflow);
   I don not think it has to be this complex;
  */

  input numchr $9.;
  put numchr;
  numchr=compress(numchr,'.');
  exact_integer=input(numchr,9.);
  put exact_integer hex16.;
  * in microcode this should be a bit shifting operation and should be exact?;
  res=round(exact_integer,10000);
  res=res/10000;
  put res 9.4;

cards4;
6274.4999
6274.5000
6274.5001
;;;;
run;quit;