Most Efficient Way to Scale an Array in Java?

java arrays performance vector multiplication
Ian Renton picture Ian Renton · Oct 17, 2011 · Viewed 14.2k times · Source

(Apologies if this has been asked before - I can't believe it hasn't, but I couldn't find one. Perhaps my search-fu is weak.)

For years I've "known" that Java has no native function to scale an array (i.e. multiply each element by a constant). So I've been doing this:

for (int i=0; i<array.length; i++) {
  array[i] = array[i] * scaleFactor;
}

Is this actually the most efficient way (in this application, for example, it's an array of around 10000 doubles)? Or is there a better way?

Answer

Jon Skeet picture Jon Skeet · Oct 17, 2011

Looks absolutely fine to me. I can't think of a more efficient way. Obviously try to put that code in one place rather than having the actual code all over the place, but other than that, no obvious problems.

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