<p dir="ltr">Hi Zhanibek,</p>
<p dir="ltr">you should not worry about that. In SCIP, the values of a variable is stored as double aka SCIPReal. This is because in the solving process real numbers are allowed even if the vartype is "binary" or "integer".</p>
<p dir="ltr">Not every integer is representable as a double as exact integral value, in fact only a very small amount of integers is.<br>
That means that a real number is used which is closest to the integer.<br>
The precision to which you print the values is high enough to make this visible. If you reduce the precision, you'll get the expected number as output (even though still not stored as an integer!).</p>
<p dir="ltr">I'd advise against adding or subtracting anything. You can cast the result to an integral type if you want to assert that the output doesn't have any weird values.</p>
<p dir="ltr">There is a small thing SCIP could do better actually: sometimes you'll get 0.9999999 instead of 1 (which is representable as double) for e.g. binary variables. In theory such output could be enforced to 0/1 or integral value once the solving process is completed. Personally I don't care about such values, because with floating point numbers you can't ever trust a result to every digit and one should accept that fact as early as possible.</p>
<p dir="ltr">I hope that this answers your question.</p>
<p dir="ltr">Stefan</p>
<div class="gmail_quote">Am 04.12.2013 06:55 schrieb "Zhanibek Datbayev" <<a href="mailto:itomatik@gmail.com">itomatik@gmail.com</a>>:<br type="attribution"><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
<div dir="ltr">Hey guys,<div><br></div><div>I'm trying to tackle a MIP problem using SCIP. All of my variables are either integer or binary, but sometimes SCIP produces non-integer values. For example below all of the values are integers except of one which gets 3491.99999999999. </div>
<div><br></div><div>Is that expected behavior? Should I not worry about this kind of values and just convert them to integers (adding 0.1 before doing that)?</div><div><br></div><div>Thanks in advance!</div><div><br></div>
<div>-Zhanibek</div><div><br></div><div><div><br></div><div>x#2#1 4215 <span style="white-space:pre-wrap"> </span>(obj:0)</div><div>x#2#5 56830 <span style="white-space:pre-wrap"> </span>(obj:0)</div>
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