How do I find the closest array element to an arbitrary (non-member) number?

Question

Seemingly similar questions: \"Finding closest number in an array\" (in Java) and \"find nearest match to array of doubles\" (actually a geography problem).

Answer 1

One way to do this using LINQ is like this:

public int GetClosestIndex( List doublelist, double targetvalue )
{
  return doublelist.IndexOf(doublelist.OrderBy(d => Math.Abs(d - targetvalue)).ElementAt(0));
}

It might have some performance issues, but If the list is not that long, it should not pose a problem. Also, if two elements are equally distant from the target value, it will return the first index of those.