guessFrac

[JVM]
open fun guessFrac(r: Double, int3: Array<Int>)

Looks for a fraction very close to some decimal value.

Tries denominators 1..1000. So answer is at least accurate to within 1/1000th. For example, .33333 -> 1/3.
For example: -1.75 -> whole=-1, numerator=-3 denominator=4
Results stored in int3[0=whole, 1=num, 2=den].
Slow if no good match found, but this does a good approximate job that gcd() might miss. ```kotlin int ar[]=new int[3]; double d=-1.75; int whole=guessFrac(d,ar); //results: ar[0]=-1, ar[1]=-3, ar[2]=4